diff --git a/python/paddle/fluid/imperative/learning_rate_scheduler.py b/python/paddle/fluid/imperative/learning_rate_scheduler.py
index 0ace448d7f884ff866085c43171acb4353ff4b91..b698e6200739f04cb56cc2c2219acfbc493bcff4 100644
--- a/python/paddle/fluid/imperative/learning_rate_scheduler.py
+++ b/python/paddle/fluid/imperative/learning_rate_scheduler.py
@@ -220,7 +220,7 @@ class NoamDecay(LearningRateDecay):
 
     def step(self):
         from .. import layers
-        a = self.create_lr_var(global_step**-0.5)
-        b = self.create_lr_var((warmup_steps**-1.5) * global_step)
-        lr_value = (d_model**-0.5) * layers.elementwise_min(a, b)
+        a = self.create_lr_var(self.step_num**-0.5)
+        b = self.create_lr_var((self.warmup_steps**-1.5) * self.step_num)
+        lr_value = (self.d_model**-0.5) * layers.elementwise_min(a, b)
         return lr_value