Abstract: The study of spatial and temporal distribution characteristics of the water requirement of crop could provide the basis for effective utilization of water resources and rational distribution of crop. Based on the meteorological data and phenological data from 13 stations of irrigation district in Ningxia Hui Autonomous Regions, ETC of main crops (spring wheat, maize, rice and winter wheat) in the whole growing period and at different growth stages during 1961 to 2010 were estimated by using FAO Penman-Monteith equation and corrected crop coefficient, and the spatial and temporal distribution characteristics of ETC were analyzed，then the irrigation requirement and water requirement rate of main crops during the growing season were analyzed. Results showed that effective precipitation showed a slightly decreasing trend in the whole growing period of rice and maize and showed a slightly increasing trend in the whole growing period of spring wheat and winter wheat. The effective precipitation of autumn grain crops was two times as much as that of summer grain crops during 1961-2010. The high value areas of effective precipitation were in Shitanjing, Lingwu and Zhongning, and the area with low effective precipitation was in Shizuishan. The order of crop water requirement in the whole growing period was rice>maize > winter wheat > spring wheat, the distribution of water requirement was similar to the irrigation requirement during each growth stage. The water requirement and irrigation requirement showed a remarkably increasing trend in the whole growing period and each growth stage, the values of high water requirement and irrigation requirement were observed in each station of Shizuishan and Zhongning. Water requirement rate significantly increased after jointing (striking root), the water requirement rate reached the maximum value at anthesis-milk stage of spring wheat and winter spring wheat and jointing-anthesis and anthesis-milk stages of maize, the water requirement rate was maintaining at a high level after jointing and reached the maximum value at milk - mature stage.