diff --git a/python/paddle/fluid/contrib/memory_usage_calc.py b/python/paddle/fluid/contrib/memory_usage_calc.py
index 09721e430b7e5bb6b9891d5272ca54475baf6157..baa14a573fcfdfa943af1e995f687c74e9fb4d07 100644
--- a/python/paddle/fluid/contrib/memory_usage_calc.py
+++ b/python/paddle/fluid/contrib/memory_usage_calc.py
@@ -70,23 +70,37 @@ def memory_usage(program, batch_size):
     if not isinstance(program, Program):
         raise TypeError(
             "Calculating Memory Usage requires Program as its Parameter."
-            "But you passed in %s" % (type(prgram)))
+            "But you passed in %s" % (type(program)))
     if batch_size <= 0:
         raise ValueError("The batch size need to be positive.")
 
     # Get the var_name list of first block and calculate
     total_memory = 0.0
-    for var in six.itervalues(program.global_block().vars):
-        data_count = 1
-        for x in var.shape:
-            if x == -1:
-                data_count *= batch_size
-            else:
-                data_count *= x
-        var_memory = data_count * dtype_to_size[var.dtype]
-        if DEBUG:
-            print("%s memory usage: %d" % (var.name, var_memory))
-        total_memory += var_memory
+    processed_var_names = set()
+    for op in program.global_block().ops:
+        for var_name in op.output_arg_names:
+            if var_name in processed_var_names:
+                continue
+            processed_var_names.add(var_name)
+            var = program.global_block().vars[var_name]
+            if var.desc.type() != core.VarDesc.VarType.LOD_TENSOR:
+                continue
+
+            data_count = 1
+            neg_dim_count = 0
+            for x in var.shape:
+                if x < 0:
+                    if neg_dim_count >= 1:
+                        raise ValueError("Var %s has more than one negtive dim."
+                                         % (var_name))
+                    neg_dim_count += 1
+                    data_count *= batch_size * (-x)
+                else:
+                    data_count *= x
+            var_memory = data_count * dtype_to_size[var.dtype]
+            if DEBUG:
+                print("%s memory usage: %d" % (var.name, var_memory))
+            total_memory += var_memory
     if DEBUG:
         print("total memory usage: %.2f" % (total_memory))