Based on the observation data from 109 meteorology stations during 1961- 2010 and phenological data of single cropping rice from 16 agrometeorological stations during 1981-2010 well spread over the rice growing regions of Sichuan Province, the effective precipitation and water requirement of single cropping rice were calculated and water deficit and water deficient ratio for the rice were analyzed in the study area. The results showed that the average water deficient ratio during 1961- 2010 from booting to flowering was the highest, followed by that from transplanting to booting, and that from flowering to maturity was the least. The effective precipitation, water requirement and water deficit during the entire growth period of rice were decreasing, but the water deficient ratio for the central and western rice- growing areas showed an increasing trend. The effective precipitation decreased during the transplanting to booting and flowering to maturity stages, but increased during the booting to flowering stage.The water requirement among the different growth stages showed a downward trend. The water deficit and water deficient ratio decreased during the booting to maturity stage, but increased during the transplanting to booting for the central and western rice-growing areas. The research can provide the basis for agricultural water use and reasonable irrigation in rice growing areas in Sichuan.