The daily precipitation information from 81 meteorological stations in the Qin-Ba Mountainous Area during 1999-2016was used to evaluate the applicability of TRMM 3B42 satellite precipitation data in Qin-Ba Mountainous area. The results indicatethat the TRMM 3B42 data show high precision in the annual, seasonal and monthly scales, and the correlation coefficients fromMarch to November all reached 0.8, nevertheless the minimum is in January (0.58). During the four seasons, the minimum R2 isin winter for only 0.75. The precipitation variation process reflected by TRMM is basically the same as the measured precipitationprocess, but there is a certain difference in precipitation amount, and TRMM has get a slightly overestimated precipitation result.According to the comparison of different rainfall levels, it is found that the satellite data have high accuracy for precipitation in themiddle and above grades, while the accuracy of no rain and light rain is slightly lower, due to the weak detection capability ofTRMM for micro-precipitation of 0.1-0.9mm. On no rain, light rain and rainstorm days, the TRMM estimating results are oppositefrom the site surveys concerning interannual variation trend, however the moderate and heavy rain days ’ are the same one. Theresearch results have important application value for the study of meteorological processes in areas lack of data in the Qin-BaMountainous Area.