Referring to the water risk assessment method presented by World Wide Fund for Nature(WWF)and German Investment and Development Limited Liability Company(DEG), the water risk assessment system was constructed, considering five aspects of water shortage risk, pollution risk, disaster risk, ecology risk, regulation risk and reputation risk. Taking 31 provinces and cities as the research objects, the water risk in each region during 2000-2013 was evaluated using weighted comprehensive assessment method. The results of water risk assessment were classified according to Fuzzy ISODATA classification model. Based on that, the overall spatial differences and temporal evolution trends of water risk indexes in China were studied using spatial self-correlation analysis method. The results show that: 1. The overall water risk in China is at low-medium level and is developing from high to low. 2. The differences among regions are obvious. In general, water risks in southern regions are lower than those in northern China. 3. The shortage and pollution risk have a strong impact on the comprehensive water risk in each region, while the impact degree is getting weaker over time and ecological risk is rising slightly. Disaster risks affected by natural conditions show randomness characteristic. 4. Water risks show a significant agglomeration in space dimension, while its features are weakening. The correlation of water risks among regions is decreasing.