diff --git a/python/paddle/dataset/imdb.py b/python/paddle/dataset/imdb.py
index 39fc29fdac8aa907ac7d1de4b84aa8b3640d903b..60a9062c4688b11f9d9252ff7a48eabfb716bd48 100644
--- a/python/paddle/dataset/imdb.py
+++ b/python/paddle/dataset/imdb.py
@@ -25,7 +25,7 @@ import collections
 import tarfile
 import re
 import string
-from six.moves import range
+import six
 
 __all__ = ['build_dict', 'train', 'test', 'convert']
 
@@ -43,13 +43,13 @@ def tokenize(pattern):
         # sequential access of member files, other than
         # tarfile.extractfile, which does random access and might
         # destroy hard disks.
-        tf = next(tarf)
+        tf = tarf.next()
         while tf != None:
             if bool(pattern.match(tf.name)):
                 # newline and punctuations removal and ad-hoc tokenization.
-                yield tarf.extractfile(tf).read().rstrip("\n\r").translate(
-                    None, string.punctuation).lower().split()
-            tf = next(tarf)
+                yield tarf.extractfile(tf).read().rstrip(six.b("\n\r")).translate(
+                    None, six.b(string.punctuation)).lower().split()
+            tf = tarf.next()
 
 
 def build_dict(pattern, cutoff):
@@ -67,7 +67,7 @@ def build_dict(pattern, cutoff):
 
     dictionary = sorted(word_freq, key=lambda x: (-x[1], x[0]))
     words, _ = list(zip(*dictionary))
-    word_idx = dict(list(zip(words, range(len(words)))))
+    word_idx = dict(list(zip(words, six.moves.range(len(words)))))
     word_idx['<unk>'] = len(words)
     return word_idx
 
diff --git a/python/paddle/fluid/framework.py b/python/paddle/fluid/framework.py
index 4e08836471ca8a3b128f609db34dff2437d4da6b..c3d2b7a4b29f080f90fd05805de0c95bc067fe80 100644
--- a/python/paddle/fluid/framework.py
+++ b/python/paddle/fluid/framework.py
@@ -905,10 +905,9 @@ class Block(object):
             Variable: the Variable with the giving name.
         """
         if not isinstance(name, six.string_types):
-            if not isinstance(name, six.binary_type):
-                raise TypeError(
-                    "var require string as parameter, but get %s instead." %
-                    (type(name)))
+            raise TypeError(
+                "var require string as parameter, but get %s instead." %
+                (type(name)))
         v = self.vars.get(name, None)
         if v is None:
             raise ValueError("var %s not in this block" % name)
diff --git a/python/paddle/fluid/tests/book_memory_optimization/test_memopt_image_classification_train.py b/python/paddle/fluid/tests/book_memory_optimization/test_memopt_image_classification_train.py
index b2a59d27da9b3348b581d51a68d769bbf3b90d35..8831dac33638848025a3e86cbc476e8a71c892bc 100644
--- a/python/paddle/fluid/tests/book_memory_optimization/test_memopt_image_classification_train.py
+++ b/python/paddle/fluid/tests/book_memory_optimization/test_memopt_image_classification_train.py
@@ -56,7 +56,7 @@ def resnet_cifar10(input, depth=32):
         return tmp
 
     assert (depth - 2) % 6 == 0
-    n = (depth - 2) / 6
+    n = (depth - 2) // 6
     conv1 = conv_bn_layer(
         input=input, ch_out=16, filter_size=3, stride=1, padding=1)
     res1 = layer_warp(basicblock, conv1, 16, 16, n, 1)
diff --git a/python/paddle/fluid/transpiler/memory_optimization_transpiler.py b/python/paddle/fluid/transpiler/memory_optimization_transpiler.py
index 20ba7ed2b0b9df0d0432727ee1f69f61533c402e..c072ef0822751f3ec90f26721e3e703a28c5d032 100644
--- a/python/paddle/fluid/transpiler/memory_optimization_transpiler.py
+++ b/python/paddle/fluid/transpiler/memory_optimization_transpiler.py
@@ -14,6 +14,7 @@
 
 from collections import defaultdict
 from .. import core
+from .. import compat
 from ..framework import Program, default_main_program, Parameter
 from ..backward import _rename_arg_
 from functools import reduce
@@ -125,15 +126,15 @@ class ControlFlowGraph(object):
 
     def _has_var(self, block_desc, var_name, is_forward):
         if is_forward:
-            return block_desc.has_var(str(var_name))
+            return block_desc.has_var(cpt.to_bytes(var_name))
         else:
-            return block_desc.has_var_recursive(str(var_name))
+            return block_desc.has_var_recursive(cpt.to_bytes(var_name))
 
     def _find_var(self, block_desc, var_name, is_forward):
         if is_forward:
-            return block_desc.find_var(str(var_name))
+            return block_desc.find_var(cpt.to_bytes(var_name))
         else:
-            return block_desc.find_var_recursive(str(var_name))
+            return block_desc.find_var_recursive(cpt.to_bytes(var_name))
 
     def _check_var_validity(self, block_desc, x, is_forward):
         if str(x) == "@EMPTY@":
@@ -258,7 +259,7 @@ class ControlFlowGraph(object):
                         # Rename the var to the cache var already with
                         # memory allocated in order to reuse the memory.
                         _rename_arg_(self._ops, x, cache_var, begin_idx=i)
-                        self._program.block(block_desc.id).var(str(
+                        self._program.block(block_desc.id).var(cpt.to_literal_str(
                             x)).desc = self._find_var(block_desc, cache_var,
                                                       is_forward)
                         self._update_graph(x, cache_var, begin_idx=i)