The issue of water resources security has become the focus of our concern.This paper present the definition and study content of the water resources security,carry out the condition study on the water resources security.Proposing that the water resources security system has self-care,pertinence and public features.Clearly the goal of safe water resources,propose the assessment theory and method of water resources security,stress and stress-response models.Set up the assessment indicator system of water resources security.Make assessment on water resources security status in different cities of Shanxi Province,propose corresponding proposals.