diff --git a/my_tree.py b/my_tree.py
index 8aa100b..e8a6f0d 100644
--- a/my_tree.py
+++ b/my_tree.py
@@ -1,8 +1,39 @@
 import turtle
 import random
 
+pen = turtle.Turtle()
+pen.color('sienna')
+pen.speed(0)
+
+w = turtle.Screen()
+w.bgcolor('wheat')
+
+pen.left(90)
+pen.up()
+pen.backward(150)    # 后退
+pen.down()
+
+tree(60)
+turtle.done()
+
 def  tree(n):
-    if n >=0:
+    if n >=12:
+        color_list = ['snow','lightcoral']
+        color=random.choice(color_list)
+        pen.color(color)
+        pen.pensize(n/10)
+    elif:
+        pen.color('sienna')
+        pen.pensize(n/10)
+    pen.forward(n)
+    angle = random()
+    pen.right(30*angle)
+    length = 1.5*random.random()
+    tree(n-10*length)
+    pen.left(60*angle)
+    tree(n-10*length)
+    pen.right(30*angle)
+
         pen.forward(n)
         pen.right(30)
         tree(n-10)
@@ -13,19 +44,6 @@ def  tree(n):
         pen.backward(n)
         pen.down()
 
-pen = turtle.Turtle()
-pen.color('sienna')
-# 画布大小
-w = turtle.Screen()
-w.bgcolor('wheat')      # wheat小麦
 
-# 移动到起点
-pen.left(90)
-pen.up()
-pen.backward(150)    # 后退
-pen.down()
-  
-tree(60)
-turtle.done()