diff --git a/behavior_tree/main.py b/behavior_tree/main.py
new file mode 100644
index 0000000..e69de29
diff --git a/behavior_tree/topLevel_BT.py b/behavior_tree/topLevel_BT.py
new file mode 100644
index 0000000..d0c77ac
--- /dev/null
+++ b/behavior_tree/topLevel_BT.py
@@ -0,0 +1,6 @@
+"""
+    于此定义顶层行为树结构（不包括实际执行，实际执行置于 main.py 中）
+"""
+
+import py_tree
+