According to the explication of the concept and characteristics of natural resources, this paper further define the nature of the science of natural resources. In line with the key question of the science, it put forward the task of the science research.Then, it expound the main contents of the science research. And on the basis of experiences of some developed countries, it gives new trends of the future research. At last, the paper expound the branch system of the science of natural resources on the basis of the relations between it and other sciences which are closed to it.