Abstract: Change of water budget for dryland crops and its response to climate change in SiChuan province for the whole growth period and key growth phases for corn, wheat, rape on each sub region last 40 years were analyzed. Based on each ten-day historical records of meteorology data, soil moisture and crops growth data in 53 agriculture-meteorological stations in Sichuan during the period between 1971 and 2009, farmland water balance and the method of climate change trends climate trend were used in five climatic sub-regions in Sichuan. The results demonstrated that during the whole growth phases and the key growth phases, wheat and rape crops were in water deficit in sub-regions, but the deficit quantity in the key growth phases showed a decreasing trend. Temperature and vapor pressure in sub-regions were presented as increasing trend, and the wind speed and sunshine hours as decreasing trend. Water budget was positively correlated with precipitation and vapor pressure and was negatively correlated with temperature, sunlight, and wind speed. It can be concluded that the water budget of dryland crops in SiChuan was shown as water deficit, however, the water deficit degree reduced with the sunlight hours and wind speed decreased.