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The temporal trend and spatial distribution of precipitation during the last 50 years are analyzed on the basis of observation data from 12 stations over the Chengdu region. The results show that significant decreasing trends could be seen in annual precipitation， precipitation intensity in wet season， and maximum daily rainfall amount. The precipitation concentrates in summer，and the precipitation in July and August accounts for 47 percent of that of the total year. The annual precipitation and maximum daily rainfall amount decrease from west to east. The MK suddenchange test is conducted for these stations， and the results show that there exist suddenchanges in annual precipitation for most stations.