在追溯水资源界定和内涵历史沿革的基础上，根据水资源评价的有效性、可控性和可再生性准则，按不同评价口径将水资源划分为广义水资源、狭义水资源、国民经济可利用量和生态环境需水量。从水资源承载的双重客体出发，一定程度上澄清了历史上关于水资源评价和定义的争论。而后从水资源科学的发展入手，刻划了水资源学研究的对象和三个层面上的内容，即基础研究、应用研究和综合研究，根据学科研究的内容，构建了包括基础学科、应用学科和综合学科的水资源学学科体系，并分别就三大组成部分作了剖析，这对于水资源学科建设具有积极的意义。

Based on the summary of the conception and connotation evolution of water resources bounded by other hydrologists, the paper divides water resources into generalized water resources, specialized water resources, useable water resources quantity for national economy and ecological water requirements on different caliber. It clears the argument on water resources assessment and definition in history from the double carrying object of water resources. And that it scores the object of water resources research and its contents on three layers proceeded with water resources development course, which includes basic research, applied research and integrated research. According to the contents of subject, the paper constructs the water resources research system consisted of base subject, application subject and integration subject and analysis three parts separately indepth. It is of positive significance for construction of water resources study.