Abstract: By using the the seasonal precipitations, the annual number of rainy days, the annual number of rainstorm days, and the annual night-rain rates from 1991 to 2020 at the National Meteorological Observation Station in Ya'an, the difference characteristics of precipitation in the past 30 years in Ya'an are analyzed. The results show the annual precipitations in Ya'an fluctuated greatly and increased linearly in general with the linear inclination rate of 54.6 mm/10a. The seasonal distribution of precipitation in Ya'an was characterized by concentrated precipitation in summer, less precipitation in winter, and moderate precipitation in spring and autumn. The precipitation in Ya'an was quite different from north to south, and central Ya'an had a humid climate with relatively large annual precipitations; the number of rainy days showed a decreasing trend and the number of rainstorm days decreased slightly in Yucheng and Tianquan while increased slightly in Mingshan, Lushan and Yingjing; the number of night-rain days was the largest with the highest value of 193.9d in Tianquan. The annual precipitation in the northern part was relatively low; the number of rainy days showed a decreasing trend and the number of rainstorm days increased slightly, while the number of night-rain days remained mediate at 149.3d. The southern part had a dry and warm climate with least annual precipitation; the number of rainy days showed a decreasing trend and the number of rainstorm days decreased slightly in Hanyuan and increased sightly in Shimian; the number of night-rain days was the least with the lowest value of 39.7d in Hanyuan.