Abstract: Based on the daily precipitation data of TRMM satellite from 1998 to 2015, the annual precipitation, seasonal precipitation, rainfall days of various grades, the interannual and seasonal changes of precipitation in the entire region, the propensity rates of different precipitation types are calculated, and then analyzed according to their temporal and spatial distribution. The results show that: 1) The average annual precipitation in Qin-Ba Mountainous Area from 1998 to 2015 shows a decreasing trend from southeast to northwest, and it shows a stripe distribution. The precipitation in the south of the mountainous area is significantly higher than that in the north, and there is no significant difference in precipitation between the east and west of the mountainous area; 2) The average precipitation in the four seasons shows the spatial distribution characteristics of “high in the south and low in the north”; 3) The number of rainless days increases in the whole mountainous area and the number of light rainy days decreases in the whole mountainous area. The number of moderate rain days increases except the southeast of the Qin-Ba Mountainous Area. The number of heavy rain days increases except for Chongqing, Henan, and northern Sichuan. The number of rainstorm days increases except the number of rainstorm days decreases in the east and west of the mountainous area. 4)The annual precipitation in the whole mountainous area increases slowly over time.