Based on the data of air temperature and precipitation from the meteorological station in Baiyin city,we utilized the Mann-Kendall method and the wavelet to analyze the climatic variation characteristics. Results showed that the temperature presented a tendency of increasing and the precipitation was fluctuated in Baiyin city. The temperature was rapidly augmented after 1987 in the study area,and the variance tendency of mean air temperature in crop growth period was consistent with the annual air temperature,but its contribution to mean annual air temperature was not big. The precipitation emerged a tendency of increasing after 1990. However,the increasing trend was not obvious. The variance tendency of precipitation in crop growth period was almost similar to the annual total precipitation,this have something to do with less rainfall and relative concentration in Baiyin city. Furthermore,there were multi-scaled periods changes for air temperature and precipitation,the specific periods were 2 ~5 years,9 ~11years and about 20 years for temperature; and it also existed 2 ~6 years,9 ~10 years and about years periods for precipitation. Therein,the decadal variability of 20 years were given priority to with the temperature and precipitation change cycle period.