Abstract: On the basis of the NCEP/NCAR monthly mean reanalysis data for global 56 years from 1948 to 2003,this paper studies the year-by-year variation characteristics and the temporal-spatial distribution characteristics of in-the-air water resource in the region of Sichuan and Chongqing(100~110°E,25~35°N),the water vapor transportation characteristics there,the water vapor receipts and expenditure condition there,the precipitation capability of the atmosphere there.The results show that:in the recent 56 years the content of the whole layer water vapor has declined a little on the whole in the region of Sichuan and Chongqing,while water vapor in summers and winters has increased gradually;in this region,the level distribution of the water vapor content performance for the wet center on Southeast Sichuan Basin to Fulin of Chongqing,which trends decreasing gradually from southeast to northwest;the water vapor transports southwest and southeast principally;the water vapor receipts and expenditure of the whole year appear clean importing;relatively large achievable precipitation amount exists in autumn,summer and spring,with abundant potential water resource in the air.