diff --git a/.gitignore b/.gitignore
index 0b5b6e5..ce689c2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,7 +3,8 @@ __pycache__/
 .claude/
 *.py[cod]
 *$py.class
-data/
+data/*
+!data/default_claude_md
 
 .env
 .env.*
diff --git a/data/default_claude_md b/data/default_claude_md
new file mode 100644
index 0000000..8a156d6
--- /dev/null
+++ b/data/default_claude_md
@@ -0,0 +1,6 @@
+# {project_name}
+
+## Guidelines
+
+- Before starting any large or complex task, present a plan to the user and wait for approval before proceeding. Do not begin implementation until the user confirms.
+- Persist important context, decisions, and project knowledge in this CLAUDE.md file rather than relying solely on session-based memory.
diff --git a/src/agent_box/config.py b/src/agent_box/config.py
index e0751f9..324bcc9 100644
--- a/src/agent_box/config.py
+++ b/src/agent_box/config.py
@@ -34,6 +34,9 @@ def weixin_state_dir(self) -> Path:
     agent_permission_mode: str = "bypassPermissions"
     agent_max_turns: int | None = None
 
+    # Default CLAUDE.md template for new projects
+    default_claude_md_path: Path = Path(__file__).resolve().parent.parent.parent / "data" / "default_claude_md"
+
 
 
 settings = Settings()
diff --git a/src/agent_box/session_manager.py b/src/agent_box/session_manager.py
index fca8d88..9e1cfc7 100644
--- a/src/agent_box/session_manager.py
+++ b/src/agent_box/session_manager.py
@@ -60,6 +60,7 @@ def create(self, name: str, agent_type: str | None = None) -> ProjectInfo:
 
         project_path = self.workspace / name
         project_path.mkdir(parents=True, exist_ok=True)
+        self._init_claude_md(project_path, name)
 
         info = ProjectInfo(
             name=name,
@@ -74,6 +75,17 @@ def create(self, name: str, agent_type: str | None = None) -> ProjectInfo:
     def get(self, name: str) -> ProjectInfo | None:
         return self._projects.get(name)
 
+    def _init_claude_md(self, project_path: Path, name: str) -> None:
+        target = project_path / "CLAUDE.md"
+        if target.exists():
+            return
+        template_path = settings.default_claude_md_path
+        if not template_path.is_file():
+            return
+        content = template_path.read_text().replace("{project_name}", name)
+        target.write_text(content)
+        log.info("initialized CLAUDE.md for project %s", name)
+
     def list_all(self) -> list[ProjectInfo]:
         return list(self._projects.values())