Water resources is an important foundation which support sustainable development of economic society, meanwhile economic society is a significant subject for water resources protection. Both of them are mutually reinforcing,and thus they should maintain harmonious. However,in many cases,there exists contradictions, so how to achieve a kind of equilibrium between them is a difficult problem. In order to solve this problem, this paper elaborates the significance of the equilibrium between water resources protection and development of economic society from the viewpoint of harmony theory. On this basis, it expounds the concept and connotation of harmony equilibrium, defined which as the relatively static and acceptable balance condition when stakeholders take their interests and the overall harmony goal into account. Furthermore,the general steps and calculation methods have been established to achieve equilibrium based on harmony theory. Finally the harmony equilibrium model was applied to Henan province to determine its harmony equilibrium condition between water resources protection and economic society development.