Abstract: Based on the 1961-2000 hourly precipitation data at 112 stations of Southwest China, frequencies and intensities of hourly precipitation and extreme hourly precipitation in four seasons were analyzed. The results show that: 1) in summer, hourly precipitation frequencies decreased in most parts of Southwest China, including the western Sichuan Basin, Yunnan and southern Guizhou, but increased in the eastern Sichuan Basin and the western Sichuan highland; the regional mean hourly precipitation frequencies decreased by 0.9% per 10 years; while extreme hourly precipitation frequencies decreased in the western Sichuan Basin, and increased in most parts of Southwest China, including the eastern Sichuan Basin, western Sichuan highland, most part of Yunnan and Guizhou; the regional mean extreme hourly precipitation frequencies increased by 2.0% per 10 years. In autumn, trends of hourly precipitation frequencies were negative in most of Southwest China; the regional mean hourly precipitation frequencies decreased by 3.5% per 10 years; however trends of extreme hourly precipitation frequencies were not obvious. 2) In summer, trends of average rainfall intensity in most parts of Southwest China, except the western Sichuan Basin, were positive; furthermore, trends of extreme hourly precipitation intensity were also positive in most parts of Southwest China. In autumn, the average rainfall intensity increased in most parts of Yunnan and Guizhou, but decreased in the eastern Sichuan Basin and the western Sichuan highland.