diff --git a/src/components/BootstrapBlazor.Region/BootstrapBlazor.Region.csproj b/src/components/BootstrapBlazor.Region/BootstrapBlazor.Region.csproj
index f2a99d7d..629c4484 100644
--- a/src/components/BootstrapBlazor.Region/BootstrapBlazor.Region.csproj
+++ b/src/components/BootstrapBlazor.Region/BootstrapBlazor.Region.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.Razor">
 
   <PropertyGroup>
-    <Version>9.0.2</Version>
+    <Version>9.0.3</Version>
   </PropertyGroup>
 
   <PropertyGroup>
diff --git a/src/components/BootstrapBlazor.Region/Components/SelectCity.razor.cs b/src/components/BootstrapBlazor.Region/Components/SelectCity.razor.cs
index c4287977..bd8f66ae 100644
--- a/src/components/BootstrapBlazor.Region/Components/SelectCity.razor.cs
+++ b/src/components/BootstrapBlazor.Region/Components/SelectCity.razor.cs
@@ -15,8 +15,6 @@ public partial class SelectCity
     [Parameter]
     public bool IsMultiple { get; set; }
 
-    private string? InputId => $"{Id}_input";
-
     private string? ClassString => CssBuilder.Default("select bb-city")
         .AddClass("disabled", IsDisabled)
         .AddClassFromAttributes(AdditionalAttributes)
@@ -42,30 +40,22 @@ private async Task OnClearValue()
 
     private void OnSelectProvince(string province)
     {
-        if (IsMultiple)
+        if (!IsMultiple)
         {
-            HashSet<string> cities;
-            if (province == "直辖市")
-            {
-                cities = Municipalities;
-            }
-            else if (province == "特别行政区")
-            {
-                cities = SpecialAdministrativeRegions;
-            }
-            else
-            {
-                cities = GetCities(province);
-            }
-            foreach (var city in cities)
-            {
-                if (!_values.Remove(city))
-                {
-                    _values.Add(city);
-                }
-            }
-            CurrentValue = string.Join(",", _values);
+            return;
+        }
+
+        HashSet<string> cities = province switch
+        {
+            "直辖市" => Municipalities,
+            "特别行政区" => SpecialAdministrativeRegions,
+            _ => GetCities(province)
+        };
+        foreach (var city in cities.Where(city => !_values.Remove(city)))
+        {
+            _values.Add(city);
         }
+        CurrentValue = string.Join(",", _values);
     }
 
     private void OnSelectCity(string item)
diff --git a/src/components/BootstrapBlazor.Region/Components/SelectCity.razor.css b/src/components/BootstrapBlazor.Region/Components/SelectCity.razor.css
index 37e1a5e6..a2a6b923 100644
--- a/src/components/BootstrapBlazor.Region/Components/SelectCity.razor.css
+++ b/src/components/BootstrapBlazor.Region/Components/SelectCity.razor.css
@@ -52,7 +52,7 @@
         }
 
 [data-bs-theme="dark"] .dropdown-menu {
-    --bb-region-body-color: #ddd;
+    --bb-region-body-color: #c0c4cc;
     --bb-region-body-hover-color: #fff;
     --bb-region-body-active-color: #fff;
     --bb-region-body-hover-bg-color: #495057;
diff --git a/src/components/BootstrapBlazor.Region/Components/SelectProvince.razor b/src/components/BootstrapBlazor.Region/Components/SelectProvince.razor
new file mode 100644
index 00000000..11434fd0
--- /dev/null
+++ b/src/components/BootstrapBlazor.Region/Components/SelectProvince.razor
@@ -0,0 +1,26 @@
+@namespace BootstrapBlazor.Components
+@inherits SelectRegionBase
+@attribute [JSModuleAutoLoader("./_content/BootstrapBlazor.Region/Components/SelectRegion.razor.js")]
+
+@if (IsShowLabel)
+{
+    <BootstrapLabel required="@Required" for="@InputId" ShowLabelTooltip="ShowLabelTooltip" Value="@DisplayText" />
+}
+<div @attributes="AdditionalAttributes" id="@Id" class="@ClassString">
+    <div class="dropdown-toggle" data-bs-toggle="bb.dropdown" data-bs-placement="@PlacementString" data-bs-offset="@OffsetString" data-bs-custom-class="@CustomClassString">
+        <input type="text" id="@InputId" disabled="@Disabled" readonly placeholder="@PlaceHolder" class="@InputClassString" value="@CurrentValueAsString" />
+        <span class="@AppendClassString"><i class="@DropdownIcon"></i></span>
+    </div>
+    @if (!IsDisabled)
+    {
+        <span class="@ClearClassString" @onclick="OnClearValue"><i class="@ClearIcon"></i></span>
+    }
+    <div class="dropdown-menu bb-region-body">
+        <ul>
+            @foreach (var item in GetProvinces())
+            {
+                <li class="@GetActiveClass(item)" @onclick="() => OnSelectProvince(item)">@item</li>
+            }
+        </ul>
+    </div>
+</div>
diff --git a/src/components/BootstrapBlazor.Region/Components/SelectProvince.razor.cs b/src/components/BootstrapBlazor.Region/Components/SelectProvince.razor.cs
new file mode 100644
index 00000000..e7b075bd
--- /dev/null
+++ b/src/components/BootstrapBlazor.Region/Components/SelectProvince.razor.cs
@@ -0,0 +1,58 @@
+// Copyright (c) BootstrapBlazor & Argo Zhang (argo@live.ca). All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+// Website: https://www.blazor.zone or https://argozhang.github.io/
+
+namespace BootstrapBlazor.Components;
+
+/// <summary>
+/// SelectProvince 组件
+/// </summary>
+public partial class SelectProvince
+{
+    /// <summary>
+    /// 获得/设置 是否可多选 默认 false 单选
+    /// </summary>
+    [Parameter]
+    public bool IsMultiple { get; set; }
+
+    private string? ClassString => CssBuilder.Default("select bb-province")
+        .AddClass("disabled", IsDisabled)
+        .AddClassFromAttributes(AdditionalAttributes)
+        .Build();
+
+    private readonly HashSet<string> _values = [];
+
+    private string? GetActiveClass(string item) => _values.Contains(item) || CurrentValue == item ? "active" : null;
+
+    private async Task OnClearValue()
+    {
+        if (IsMultiple)
+        {
+            _values.Clear();
+        }
+        CurrentValue = "";
+
+        if (OnClearAsync != null)
+        {
+            await OnClearAsync();
+        }
+    }
+
+    private void OnSelectProvince(string item)
+    {
+        if (IsMultiple)
+        {
+            if (!_values.Remove(item))
+            {
+                _values.Add(item);
+            }
+            CurrentValue = string.Join(",", _values);
+        }
+        else
+        {
+            CurrentValue = item;
+        }
+    }
+
+    private HashSet<string> GetProvinces() => RegionService.GetProvinces();
+}
diff --git a/src/components/BootstrapBlazor.Region/Components/SelectProvince.razor.css b/src/components/BootstrapBlazor.Region/Components/SelectProvince.razor.css
new file mode 100644
index 00000000..267f0e72
--- /dev/null
+++ b/src/components/BootstrapBlazor.Region/Components/SelectProvince.razor.css
@@ -0,0 +1,66 @@
+.bb-province {
+    position: relative;
+}
+
+    .bb-province:not(.disabled):hover .form-select-append {
+        display: none;
+    }
+
+.dropdown-menu {
+    --bs-dropdown-padding-y: 0;
+    --bb-region-body-color: #495057;
+    --bb-region-body-hover-bg-color: #e9ecef;
+    --bb-region-body-active-bg-color: #dee2e6;
+    --bb-region-body-hover-color: #000;
+    --bb-region-body-active-color: #000;
+    --bb-region-body-width: 400px;
+    --bb-region-body-padding: .5rem;
+    --bb-region-body-item-padding: 3px 12px;
+    --bb-region-body-gap: 5px;
+}
+
+    .dropdown-menu ul {
+        margin: 0;
+        padding: 0;
+    }
+
+    .dropdown-menu li {
+        list-style: none;
+        transition: background-color .3s linear, color .3s linear;
+    }
+
+[data-bs-theme="dark"] .dropdown-menu {
+    --bb-region-body-color: #c0c4cc;
+    --bb-region-body-hover-color: #fff;
+    --bb-region-body-active-color: #fff;
+    --bb-region-body-hover-bg-color: #495057;
+    --bb-region-body-active-bg-color: #6c757d;
+}
+
+.bb-region-body {
+    padding: var(--bb-region-body-padding);
+    width: var(--bb-region-body-width);
+}
+
+    .bb-region-body ul {
+        display: flex;
+        flex-wrap: wrap;
+        gap: var(--bb-region-body-gap);
+    }
+
+    .bb-region-body ul li {
+        padding: var(--bb-region-body-item-padding);
+        border-radius: var(--bs-border-radius);
+        color: var(--bb-region-body-color);
+        cursor: pointer;
+    }
+
+        .bb-region-body ul li:hover {
+            background-color: var(--bb-region-body-hover-bg-color);
+            color: var(--bb-region-body-hover-color);
+        }
+
+        .bb-region-body ul li.active {
+            background-color: var(--bb-region-body-active-bg-color);
+            color: var(--bb-region-body-active-color);
+        }
diff --git a/src/components/BootstrapBlazor.Region/Components/SelectRegion.razor.cs b/src/components/BootstrapBlazor.Region/Components/SelectRegion.razor.cs
index de778f56..d7fd97d3 100644
--- a/src/components/BootstrapBlazor.Region/Components/SelectRegion.razor.cs
+++ b/src/components/BootstrapBlazor.Region/Components/SelectRegion.razor.cs
@@ -9,8 +9,6 @@ namespace BootstrapBlazor.Components;
 /// </summary>
 public partial class SelectRegion
 {
-    private string? InputId => $"{Id}_input";
-
     private string? ClassString => CssBuilder.Default("select bb-region")
         .AddClass("disabled", IsDisabled)
         .AddClassFromAttributes(AdditionalAttributes)
diff --git a/src/components/BootstrapBlazor.Region/Components/SelectRegion.razor.css b/src/components/BootstrapBlazor.Region/Components/SelectRegion.razor.css
index e19b5261..5b7aaa74 100644
--- a/src/components/BootstrapBlazor.Region/Components/SelectRegion.razor.css
+++ b/src/components/BootstrapBlazor.Region/Components/SelectRegion.razor.css
@@ -35,7 +35,7 @@
 [data-bs-theme="dark"] .dropdown-menu {
     --bb-region-header-hover-bg-color: #495057;
     --bb-region-header-active-bg-color: #6c757d;
-    --bb-region-body-color: #ddd;
+    --bb-region-body-color: #c0c4cc;
     --bb-region-body-hover-color: #fff;
     --bb-region-body-active-color: #fff;
     --bb-region-body-hover-bg-color: #495057;
diff --git a/src/components/BootstrapBlazor.Region/Components/SelectRegionBase.cs b/src/components/BootstrapBlazor.Region/Components/SelectRegionBase.cs
index 3aa2f320..c2a05f92 100644
--- a/src/components/BootstrapBlazor.Region/Components/SelectRegionBase.cs
+++ b/src/components/BootstrapBlazor.Region/Components/SelectRegionBase.cs
@@ -83,6 +83,11 @@ public abstract class SelectRegionBase : PopoverSelectBase<string>
         .AddClass($"text-danger", IsValid.HasValue && !IsValid.Value)
         .Build();
 
+    /// <summary>
+    /// 获得 选择框组件 Id
+    /// </summary>
+    protected string InputId => $"{Id}_input";
+
     /// <summary>
     /// <inheritdoc/>
     /// </summary>
diff --git a/src/components/BootstrapBlazor.Region/Services/DefaultRegionService.cs b/src/components/BootstrapBlazor.Region/Services/DefaultRegionService.cs
index 66a2acaa..bcd58ec3 100644
--- a/src/components/BootstrapBlazor.Region/Services/DefaultRegionService.cs
+++ b/src/components/BootstrapBlazor.Region/Services/DefaultRegionService.cs
@@ -10,22 +10,16 @@ namespace BootstrapBlazor.Components;
 
 class DefaultRegionService : IRegionService
 {
-    private static readonly ConcurrentDictionary<string, HashSet<string>> _citiesCache = new();
-    private static readonly ConcurrentDictionary<string, HashSet<CountyItem>> _countiesCache = new();
-    private static readonly ConcurrentDictionary<string, HashSet<string>> _detailCache = new();
+    private static readonly ConcurrentDictionary<string, HashSet<string>> CitiesCache = new();
+    private static readonly ConcurrentDictionary<string, HashSet<CountyItem>> CountiesCache = new();
+    private static readonly ConcurrentDictionary<string, HashSet<string>> DetailCache = new();
 
-    private static bool _initialized = false;
+    private static bool _initialized;
 
 #if NET9_0_OR_GREATER
-    private static readonly Lock _lock = new();
+    private static readonly Lock Lock = new();
 #else
-    private static readonly object _lock = new();
-#endif
-
-#if NET9_0_OR_GREATER
-    private static readonly Lock _lockDetail = new();
-#else
-    private static readonly object _lockDetail = new();
+    private static readonly object Lock = new();
 #endif
 
     public HashSet<string> GetProvinces() => Provinces;
@@ -33,18 +27,18 @@ class DefaultRegionService : IRegionService
     public HashSet<string> GetCities(string province)
     {
         LoadCityData();
-        return _citiesCache.TryGetValue(province, out var cities) ? cities : [];
+        return CitiesCache.TryGetValue(province, out var cities) ? cities : [];
     }
 
     public HashSet<CountyItem> GetCounties(string city)
     {
         LoadCityData();
-        return _countiesCache.TryGetValue(city, out var counties) ? counties : [];
+        return CountiesCache.TryGetValue(city, out var counties) ? counties : [];
     }
 
     public HashSet<string> GetDetails(string countyCode)
     {
-        return _detailCache.GetOrAdd(countyCode, LoadDetailData);
+        return DetailCache.GetOrAdd(countyCode, LoadDetailData);
     }
 
     private static HashSet<string> LoadDetailData(string countyCode)
@@ -71,7 +65,7 @@ private static void LoadCityData()
     {
         if (!_initialized)
         {
-            lock (_lock)
+            lock (Lock)
             {
                 if (!_initialized)
                 {
@@ -105,7 +99,7 @@ private static void LoadDataCore(Stream data)
 
                 var mem = content.AsMemory();
                 var code = Trim(mem[0..index].ToString());
-                var value = Trim(mem[(index + 1)..(mem.Length - 1)].ToString());
+                var value = Trim(mem[(index + 1)..^1].ToString());
 
                 if (code[2..] == "0000")
                 {
@@ -117,7 +111,7 @@ private static void LoadDataCore(Stream data)
                         cities.Add(value);
                     }
 
-                    _citiesCache.TryAdd(value, cities);
+                    CitiesCache.TryAdd(value, cities);
                     counties = null;
                     continue;
                 }
@@ -126,14 +120,14 @@ private static void LoadDataCore(Stream data)
                 {
                     cities.Add(value);
                     counties = [];
-                    _countiesCache.TryAdd(value, counties);
+                    CountiesCache.TryAdd(value, counties);
                     continue;
                 }
 
                 if (counties == null)
                 {
                     counties = [];
-                    _countiesCache.TryAdd(city, counties);
+                    CountiesCache.TryAdd(city, counties);
                 }
 
                 counties.Add(new CountyItem() { Name = value, Code = code });