diff --git a/.changeset/usemap-optional-initial-state.md b/.changeset/usemap-optional-initial-state.md
new file mode 100644
index 00000000..92a3b94d
--- /dev/null
+++ b/.changeset/usemap-optional-initial-state.md
@@ -0,0 +1,5 @@
+---
+'react-simplikit': patch
+---
+
+Mark `useMap`'s `initialState` parameter as optional in the JSDoc and documentation, matching its existing default of `new Map()`.
diff --git a/packages/plugin/skills/react-simplikit/references/useMap.md b/packages/plugin/skills/react-simplikit/references/useMap.md
index ab50cf3d..b53e4782 100644
--- a/packages/plugin/skills/react-simplikit/references/useMap.md
+++ b/packages/plugin/skills/react-simplikit/references/useMap.md
@@ -6,13 +6,14 @@ Provides efficient state management and stable action functions.
 ## Interface
 
 ```ts
-function useMap<K, V>(initialState: MapOrEntries<K, V>): UseMapReturn<K, V>;
+function useMap<K, V>(
+  initialState: MapOrEntries<K, V> = new Map()
+): UseMapReturn<K, V>;
 ```
 
 ### Parameters
 
 <Interface
-  required
   name="initialState"
   type="MapOrEntries<K, V>"
   description="Initial Map state (Map object or array of key-value pairs)"
diff --git a/packages/react-simplikit/src/hooks/useMap/es/useMap.md b/packages/react-simplikit/src/hooks/useMap/es/useMap.md
index 0ca9cece..37333084 100644
--- a/packages/react-simplikit/src/hooks/useMap/es/useMap.md
+++ b/packages/react-simplikit/src/hooks/useMap/es/useMap.md
@@ -6,13 +6,14 @@ Proporciona una gestión eficiente del estado y funciones de acción estables.
 ## Interfaz
 
 ```ts
-function useMap<K, V>(initialState: MapOrEntries<K, V>): UseMapReturn<K, V>;
+function useMap<K, V>(
+  initialState: MapOrEntries<K, V> = new Map()
+): UseMapReturn<K, V>;
 ```
 
 ### Parámetros
 
 <Interface
-  required
   name="initialState"
   type="MapOrEntries<K, V>"
   description="Estado inicial del Map (objeto Map o arreglo de pares clave-valor)"
diff --git a/packages/react-simplikit/src/hooks/useMap/ja/useMap.md b/packages/react-simplikit/src/hooks/useMap/ja/useMap.md
index 15f0fe65..b7cc8df1 100644
--- a/packages/react-simplikit/src/hooks/useMap/ja/useMap.md
+++ b/packages/react-simplikit/src/hooks/useMap/ja/useMap.md
@@ -6,13 +6,14 @@
 ## インターフェース
 
 ```ts
-function useMap<K, V>(initialState: MapOrEntries<K, V>): UseMapReturn<K, V>;
+function useMap<K, V>(
+  initialState: MapOrEntries<K, V> = new Map()
+): UseMapReturn<K, V>;
 ```
 
 ### パラメータ
 
 <Interface
-  required
   name="initialState"
   type="MapOrEntries<K, V>"
   description="Map の初期状態（Map オブジェクトまたはキーと値のペアの配列）です。"
diff --git a/packages/react-simplikit/src/hooks/useMap/ko/useMap.md b/packages/react-simplikit/src/hooks/useMap/ko/useMap.md
index 0c0ab92e..74c77ebf 100644
--- a/packages/react-simplikit/src/hooks/useMap/ko/useMap.md
+++ b/packages/react-simplikit/src/hooks/useMap/ko/useMap.md
@@ -5,13 +5,14 @@
 ## 인터페이스
 
 ```ts
-function useMap<K, V>(initialState: MapOrEntries<K, V>): UseMapReturn<K, V>;
+function useMap<K, V>(
+  initialState: MapOrEntries<K, V> = new Map()
+): UseMapReturn<K, V>;
 ```
 
 ### 파라미터
 
 <Interface
-  required
   name="initialState"
   type="MapOrEntries<K, V>"
   description="초기 맵 상태 (맵 객체 또는 키-값 쌍의 배열)"
diff --git a/packages/react-simplikit/src/hooks/useMap/useMap.md b/packages/react-simplikit/src/hooks/useMap/useMap.md
index ab50cf3d..b53e4782 100644
--- a/packages/react-simplikit/src/hooks/useMap/useMap.md
+++ b/packages/react-simplikit/src/hooks/useMap/useMap.md
@@ -6,13 +6,14 @@ Provides efficient state management and stable action functions.
 ## Interface
 
 ```ts
-function useMap<K, V>(initialState: MapOrEntries<K, V>): UseMapReturn<K, V>;
+function useMap<K, V>(
+  initialState: MapOrEntries<K, V> = new Map()
+): UseMapReturn<K, V>;
 ```
 
 ### Parameters
 
 <Interface
-  required
   name="initialState"
   type="MapOrEntries<K, V>"
   description="Initial Map state (Map object or array of key-value pairs)"
diff --git a/packages/react-simplikit/src/hooks/useMap/useMap.ts b/packages/react-simplikit/src/hooks/useMap/useMap.ts
index 1e60a994..d4ad8fba 100644
--- a/packages/react-simplikit/src/hooks/useMap/useMap.ts
+++ b/packages/react-simplikit/src/hooks/useMap/useMap.ts
@@ -34,7 +34,7 @@ type UseMapReturn<K, V> = [Omit<Map<K, V>, 'set' | 'clear' | 'delete'>, MapActio
  *
  * @template K - The type of the Map keys.
  * @template V - The type of the Map values.
- * @param {MapOrEntries<K, V>} initialState - Initial Map state (Map object or array of key-value pairs)
+ * @param {MapOrEntries<K, V>} [initialState=new Map()] - Initial Map state (Map object or array of key-value pairs)
  * @returns {UseMapReturn<K, V>} A tuple containing the Map state and actions to manipulate it
  *
  * @example
diff --git a/packages/react-simplikit/src/hooks/useMap/zh-Hans/useMap.md b/packages/react-simplikit/src/hooks/useMap/zh-Hans/useMap.md
index a36d74e9..088139c5 100644
--- a/packages/react-simplikit/src/hooks/useMap/zh-Hans/useMap.md
+++ b/packages/react-simplikit/src/hooks/useMap/zh-Hans/useMap.md
@@ -5,13 +5,14 @@
 ## 接口
 
 ```ts
-function useMap<K, V>(initialState: MapOrEntries<K, V>): UseMapReturn<K, V>;
+function useMap<K, V>(
+  initialState: MapOrEntries<K, V> = new Map()
+): UseMapReturn<K, V>;
 ```
 
 ### 参数
 
 <Interface
-  required
   name="initialState"
   type="MapOrEntries<K, V>"
   description="初始 Map 状态（Map 对象或键值对数组）"