Abstract: Cooperative governance of trans-county public service is an inevitable choice to promote the equalization of regional public service and the modernization of local governance capacity. Regarded as a microcosm of the cooperative governance of trans-county public service， “Five water shared governance” in Zhejiang Province is taken for the research sample， whose experience of overall linkage flood control is elaborated. It is concluded that the cooperative governance of trans-county public service is faced with four challenges， i.e.， the weakness in sustainability， the game of interests between the governments， the lack of cooperation between the governments， enterprises and citizens， and the weak foundation of the legal system. Following the analytical framework of holistic governance theory， the action logic of the cooperative governance of trans-county public service is explored—by strengthening coordination and integration between governance subjects， constructing compound governance modes， promoting the legalization process， improving the performance appraisal system， and using information technology， the quality of cooperative governance of trans-county public service may be enhanced.

Key words: trans-county governance, public service, cooperative governance, holistic governance