Abstract: The difficulty in policy implementation of Chinas grass-roots governments has increasingly become a systemic problem in the administration. The top-down policy cannot overcome the obstacle of “the last kilometer” and the policy effectiveness hardly reaches its object， resulting in the central governments loss of authority and trust crisis. By analyzing the difficulty in policy implementation from the perspective of social construction theory， it was found that the main causes are the invalidation of key elements， the traditional bureaucratic constraints and policy box sealing. It was suggested that to help the grass-roots governments out of this difficulty and achieve good governance， the value of social knowledge should be explored， the order of policy implementation should be maintained by social interaction， the socialized learning in the administration should be emphasized， the process of policy implementation should be reinforced and the policy output should be strengthened.

Key words: social construction theory, grass-roots government, policy implementation, conversational participation