diff --git a/my_tree.py b/my_tree.py
index 823dbfc..a193a8b 100644
--- a/my_tree.py
+++ b/my_tree.py
@@ -1,4 +1,5 @@
 import turtle
+import random
 
 pen = turtle.Turtle()
 pen.color('sienna')
@@ -11,5 +12,27 @@ pen.left(90)
 pen.up()
 pen.backward(150)    # 后退
 pen.down()
-
+def tree(n):
+    if n>=50:
+        pen.forward(n)
+        pen.right(30)
+        tree(n-10)
+        pen.left(60)
+        tree(n-10)
+        pen.right(30)    
+        pen.up()
+        pen.backward(n)
+        pen.down()
+        
+tree(100)
+# pen.fd(100)
+# pen.right(30)
+# pen.fd(50)
+# pen.backward(50)
+# pen.left(60)
+# pen.fd(50)
+# pen.up()
+# pen.backward(50)
+# pen.right(30)
+# pen.backward(100)
 turtle.done()