Abstract: Based on the observational data of 110 meteorological stations from 1951 to 2000 in Northwest China,the changes of temperature and precipitation were analyzed with wavelet analysis.The results indicated that the change period of annual mean temperature was 15 years in Northeast China,which also had a short period with 2～4 years.The precipitation in Northeast China during recent 50 years could be divided into three stages.The annual average temperature increased with an extent of 0.6 ℃ per ten years.The increase of temperature was highest in spring,followed in winter.The precipitation decreased with an extent of 0.27 mm per year.While the precipitation increased slightly in spring,it decreased in summer and autumn.