Abstract: In order to address the issue that the water resources carrying capacity varies with the change of the relationship between carrying ability, carrying pressure and regulation ability of water resources accordingly, this article analyzed three systems relating to water resources carrying capacity (i. e., carrying ability system, carrying pressure system and regulation ability system), and further, established an index system for evaluation, which is based on the analysis of the theory, characteristics and influencing factors of water resources carrying capacity. In addition, this article developed the water resources carrying capacity evaluation model from the view of carrying standard. This model also considered water availability under different guarantee rates of utilization of water resources and different loading levels of carrying objects simultaneously. The population and the size of economy that water resources could support under different water availability and carrying standard in Shaanxi Province were calculated by the application of this model. The results could provide theoretical reference for reasonable allocation of water resources in Shaanxi Province. The practical application showed that the water resources carrying capacity evaluation model is simple and easy to use under different carrying standards, and it has good application effects as well.