Land use and land cover change (LUCC) is one of the important aspects in global change research,and it plays a key role in the regional environmental protection and economy by carrying out the study of regional spatio - temporal LUCC. In order to analyze spatio - temporal LUCC in the Fuxian Lake watershed from 1974 to 2014,the authors took a total of 10 periods of remote sensing images as the main data sources,consulted the first national geographic conditions census data,and acquired the LUCC information by using supervised classification and artificial interpretation from remote sensing images. At last, the authors further revealed the driving force mechanism by analyzing regional spatio - temporal LUCC in the past 40 years in the Fuxian Lake watershed based on socioeconomic data by principal component analysis and linear regression analysis methods. Some conclusions have been reached: With the increasing of human social and economic activities,garden land,housing construction area,roads and structures,artificial pile digging,a desert with bare surface increased significantly,while the cultivated land,forest land,grassland and water showed a trend of decrease in the Fuxian Lake watershed in the past 40 years. The LUCC changed significantly from 1990 to 1996 and 1996 to 2006,while the change was insignificant from 1974 to1977. From the result of transition of LUCC types,it can be concluded that the transitional ratio of forest land,grassland and farmland were more than other types of land,while water had steady condition. The LUCC is mainly affected by social and economic factors.