diff --git a/python/paddle/v2/layer.py b/python/paddle/v2/layer.py
index 1e4efedde363f20fde168941adcb6e8a594b533a..a91c6586a48aae4c692088e52d179efe4f69dbdd 100644
--- a/python/paddle/v2/layer.py
+++ b/python/paddle/v2/layer.py
@@ -53,7 +53,7 @@ import data_type
 __all__ = ['parse_network', 'data']
 
 
-def parse_network(*outputs):
+def parse_network(*outputs, **kwargs):
     """
     Parse all output layers and then generate a ModelConfig object.
 
@@ -75,6 +75,11 @@ def parse_network(*outputs):
         """
         context = dict()
         real_output = [each.to_proto(context=context) for each in outputs]
+        extra_layers = kwargs.get('extra_layers', None)
+        if extra_layers is not None:
+            extra_output = [
+                each.to_proto(context=context) for each in extra_layers
+            ]
         conf_helps.outputs(real_output)
 
     return __parse__(__real_func__)
diff --git a/python/paddle/v2/topology.py b/python/paddle/v2/topology.py
index f0679c5675b0c0f24f28f3df22efd4eb51ccbb3a..3e6fded839bf2ca0ddc263af1345e8216b7d2a94 100644
--- a/python/paddle/v2/topology.py
+++ b/python/paddle/v2/topology.py
@@ -53,14 +53,23 @@ class Topology(object):
     and network configs.
     """
 
-    def __init__(self, layers):
-        if not isinstance(layers, collections.Sequence):
-            __check_layer_type__(layers)
-            layers = [layers]
-        for layer in layers:
-            __check_layer_type__(layer)
+    def __init__(self, layers, extra_layers=None):
+        def __check__(layers):
+            if not isinstance(layers, collections.Sequence):
+                __check_layer_type__(layers)
+                layers = [layers]
+            for layer in layers:
+                __check_layer_type__(layer)
+            return layers
+
+        layers = __check__(layers)
         self.layers = layers
-        self.__model_config__ = v2_layer.parse_network(*layers)
+        if extra_layers is not None:
+            extra_layers = __check__(extra_layers)
+            self.layers.extend(extra_layers)
+
+        self.__model_config__ = v2_layer.parse_network(
+            *layers, extra_layers=extra_layers)
         assert isinstance(self.__model_config__, ModelConfig)
 
     def proto(self):
diff --git a/python/paddle/v2/trainer.py b/python/paddle/v2/trainer.py
index 4e432a52b209c825ca1b74393cd607db8f884f4f..cccb00794acdf936d2e11e68ae1573f99a8a5155 100644
--- a/python/paddle/v2/trainer.py
+++ b/python/paddle/v2/trainer.py
@@ -39,7 +39,7 @@ class SGD(object):
     :type parameters: paddle.v2.parameters.Parameters
     """
 
-    def __init__(self, cost, parameters, update_equation):
+    def __init__(self, cost, parameters, update_equation, extra_layers=None):
 
         if not isinstance(parameters, v2_parameters.Parameters):
             raise TypeError('parameters should be parameters')
@@ -47,7 +47,7 @@ class SGD(object):
         if not isinstance(update_equation, v2_optimizer.Optimizer):
             raise TypeError("update equation parameter must be "
                             "paddle.v2.optimizer.Optimizer")
-        topology = Topology(cost)
+        topology = Topology(cost, extra_layers=extra_layers)
         self.__optimizer__ = update_equation
         self.__topology__ = topology
         self.__parameters__ = parameters