Abstract:By using the direct homogeneity test (based on the observation data and the t test) and 3 indirect homogeneity methods(including SNHT,PMTT and PMFT),time series of annual mean wind speed at 2 meteorological stations,Tianchang and Susong,from 1957 to 2010,have been tested respectively.The results show that station relocation,observational environment change,instruments updating and measurements variation can all influence the homogeneity of the mean wind speed,and the impact of measurements updating is the most prominent factor.Because based on observation data from meteorological stations,the results of direct test is more reliable.However,SNHT,PMTT and PMFT are effective in identifying the change-points,but the missing ratio is also of a high degree.Thus,to test mean wind speed homogeneity,if the observation data from meteorological stations are correct and intact,the direct test should be used firstly and then other methods can be used additionally.