Based on the climatic data of 5 meteorological stations in Hami from 1961 to 2007，the fundamental change characteristics of various climatic element, such as temperatures, precipitation, sunshine hours, wind speed, relative humidity, potential evapotranspiration, and surface aridity are analyzed by using the linear regression, wavelet analysis and abrupt change detection methods in Hami in the resent 47 years. The main results are as follows: (1) The annual mean temperature, precipitation and relative humidity were increasing, but the annual sunshine hours and wind speed were decreasing.（2）The correlation analysis shows that there was significant positive correlation between potential evapotranspiration and annual mean temperature, annual sunshine hour and mean wind speed, and significant negative correlation between potential evapotranspiration and annual rainfall and relative humidity. Owing to the comprehensive influence of the above climatic factors, the potential evapotranspiration and surface aridity were significantly decreasing. (3) The abrupt change examination indicates that the annual mean temperature, precipitation had sudden increases in 1970 and 1965, and average wind speed, annual potential evapotranspiration and surface aridity had sudden decreases in 1980 and 1975, respectively. To sum up the sudden change characteristic of temperature and surface aridity, there occurred a “warmwet” sudden change in 1973〖CD*2〗1975. (4) There existed periodic changes of various time scales in various climatic elements and potential evapotranspiration and surface aridity in Hami.