By adopting the methods of moving average, trend analysis, wavelet transform and MannKendall method, the characteristics of interannual and interdecadal c han ges of precipitation and temperature in the area from Sanmenxia to Huayuankou (h ereafter abbreviated to “Sanhuajian” area) in the middle reaches of Yellow Riv er are analyzed with precipitation and temperature data of 21 weather stations i n this area from 1955 to 2006. The results are as follows：Firstly， the interdecadal change of average temperature is getting warm in the recent 50 more years，the late 1950s to 1980s is a cold period，whereas after 1990s is a warm period，the transition from cold to warm occurred in 1994.The period fro m 2001 to now is the warmest；The annual and seasonal mean temperatures in winte r, spring and autumn all show the trend of increasing, and occurrence of warming begins especially early and remarkably in winter. Secondly，The interdecadal c hange of precipitation is that the late 1950s to 1960s and the years after 2001 are rainy periods, whereas 1970s to 1990s is a less rain period, and particularl y, the precipitation in 1990s is the least；Seasonal precipitations all show the trend of decreasing except winter, and it decreases especially remarkably in su mmer. Thirdly，the main trend of climate change in “Sanhuajian” area is becom i ng warm and dry，but the fact that more precipitation appears after 2003 may ind icates the possibility of warming and humidifying in the coming years.