Abstract:Chongqing City is a typical area with complicated terrain. The accuracy of TRMM(Tropical Rainfall Measuring Mission) 3B43 precipitation data has been verified by period of year, season and month through the data getting from 34 meteorological stations and the impact of elevation and slope on the result of monthly scale were analyzed. The results shows:(1) Counted by year, TRMM 3B43 annual precipitation is generally more than the measured data(on average more than 5.86%), and in Western Chongqing City and Southern Chongqing City are more accurate than in Northeastern Chongqing City. Meanwhile, by season, the precipitation of autumn is more accurate than that of the other three seasons. For the month scale, the relation between TRMM 3B43 monthly precipitation data and the measured precipitation was obvious(R=0.85).(2) From each meteorological station, the data are more accurate in the researched areas, and the correlation coefficients are higher than 0.8.(3) As the altitude increases, the correlation coefficient R shows a "increase-decrease-increase" trend, and the absolute deviation is decreasing. However when the gradient increases, the absolute deviation shows a "increase-decrease-increase" trend, and the absolute deviation exhibits linear increasing trend.(4) Analysis by using principal component shows that the impact of elevation on data accuracy was greater then that of slope.