It detected the canopy temperature of rice via automated infrared imaging technology in the test under different irrigation condition, and used theCWSItheoretical model to diagnose whether the crop suffered water stress or not. It also analyzed the water stress index theoretical model of crop and other indexes on reflecting the water status of crop, including the relationship between theCWSIand leaf stomatal resistance, theCWSIand leaf net photosynthetic rate, and theCWSIand the soil moisture content. The results showed that the relations between the surface theoretical model and the above indexes were fine. It meant theCWSIwell reflected the features of water stress of rice.