diff --git a/doc/fluid/beginners_guide/programming_guide/programming_guide.md b/doc/fluid/beginners_guide/programming_guide/programming_guide.md
index b17414a6fae90a0440ce3f8439a8a92e73bba894..8df650b50cffa7644f7fcc34d37cae5389906e23 100644
--- a/doc/fluid/beginners_guide/programming_guide/programming_guide.md
+++ b/doc/fluid/beginners_guide/programming_guide/programming_guide.md
@@ -384,6 +384,8 @@ outs = exe.run(
     #定义损失函数
     cost = fluid.layers.square_error_cost(input=y_predict,label=y)
     avg_cost = fluid.layers.mean(cost)
+    #定义优化方法
+    sgd_optimizer = fluid.optimizer.SGD(learning_rate=0.01)
     #参数初始化
     cpu = fluid.core.CPUPlace()
     exe = fluid.Executor(cpu)