Abstract: Water resources have typical characteristics of quasi-public and externality.However,because water resources in a river basin are divided by different administrative regions,regional conflicts of interest and disputes over pollution control are easy to occur in their jurisdiction and governance,thus hindering the process of water pollution control in the river basin.Therefore,how to establish a collaborative governance mechanism,coordinate the interest relations and conflicts among the main bodies,and compensate the adverse effects brought by the division of public property of water resources and administrative system is of great significance for the water pollution control in the river basin.Based on the existing theoretical basis,this paper analyzes the practical reasons for the dilemma of water pollution control in the river basin,including the defects of the governance system and mechanism as well as the unsound legal system.It is concluded that a new model of collaborative governance should be established,including system collaboration,power collaboration,platform collaboration and consciousness collaboration.

Key words: river basin, water pollution, management, synergy mechanism