Abstract: At present, the emerging interest in irrigation science study is focused on automated monitoring and diagnosis of crop water status, which is essential to carrying out precise irrigation control. This paper reviews the development of methods(canopy temperature, spectral reflectance, microvariations of stem diameter, sap flow, etc.)to automatically monitor crop water status, meanwhile, their principles, advantages and disadvantages are introduced. The practical problems existing in the application of crop water status indicators for irrigation management are pointed out. In order to realize irrigation automation, the study of basis theory should be strengthened, reasonable complete index systems of crop water diagnosis should be established and precise and reliable equipment for monitoring crop water status should be developed.