This essay makes a high-level,multiaspect synthetic study on the relation of population and resources through building system dynamics model of carrying population capacity of land resources in Qinghai Province on the basis of theory of resource-resource ecology-resource economy science,on the three main levels(balance relation among all kinds of the resources,mate relation of agriculture structure and resource,forecast of per unit yield potentiality and simulation of total yield potentiality). From the beginning of synthetic analysis of system condition of population carrying capacity of land resource,this essay builds simulating models of seven sub-systems, such as water and land resource,plantry,animal husbandry,fishery,consumption and population,etc.Through revealing the relation and affection which changed accompany with time between the factors in the population carrying capacity to discribe correctly the relation between the sub-system and inner subsystems that mentioned before,thus build tendency model of this area on population carrying capacity of land resource.This essay gets a series of rational results for the changing tendency of carrying capacity of land resource and makes a primary study.