Abstract: By using Reliability Test, Validity Test and SEM Analysis, this paper tried to discuss the mutual influences between environment, government and relationship, as well as their respective impacts on synergy of local governments. The results showed that partner ability and public demand were the main external concerns whether government chose to cooperate or not. Trust and dependence objectively contributed to synergy, and public service quality and response were the internal driving force of synergy. However, public service complexity did not necessarily lead to cooperation.