Based on the daily wind speed observation data of 110 stations,this paper studies in temporal changes of wind speed and its influencing factors in Southwest China from 1969 to 2009. The results show that there was a statistically significant decrease of 0.24 m s^-1 10a^-1 in the annual mean wind speed in Southwestern China from 1969 to 2009. The annual average wind speed of 0.37 m s^-1 10a^-1 rate decreased from 1969 to 2000,while the wind speed increased of 0.55 m s^-1 10a^-1 from 2001 to 2009. The pattern of seasonal changes of wind speed was similar. From 1969 to 2009,there was a significant reduced in wind speed,the wind speed decreased from 1969 to 2000,while the wind speed increased from 2001 to 2009. On the spatial distribution of it,from 1969 to 2009 the annual wind speed reducing stations were mainly located in high altitude area,reducing the magnitude of the performance gradually decreasing from west to east,reflecting the impact of the terrain. From 1969 to 2000,the wind speed reducing stations were mainly located in the Tibetan Plateau,Hengduan Mountains and the Yunnan Plateau,the wind speed increases stations were located in Guizhou Plateau and the Sichuan Basin. From 2001 to 2009,the wind speed increases stations were mainly located in Yunnan Plateau,Hengduan Mountains and the Sichuan Basin,reducing wind stations were mainly located in the Tibetan Plateau and Guizhou Plateau. On the one hand,the analysis have confirmed that the decreasing wind speed was caused mainly by the decreasing monsoon circulation and Westerlies from 1969 to 2000,and the strengthening latitudinal wind speed has made some contributions on the increasing wind speed after 2000. And what's more,the strengthening Tibetan monsoon has also made some contributions to wind change. On the other hand,regional warming was the key incentive for wind decreased. Warming temperatures rose,especially the lowest temperature significantly warming was the main reason that results in the decrease of wind speed,and further analysis revealed that weaken of the pressure gradient between the different latitudes is the key factor of reducing the wind speed.