Global drylands are characterized by the scarcity of precipitation and the fragile ecological environment. They play the important roles in global climate change and ecosystem regulation. It could contribute to protecting the environment and improving the living standards of local people to detecte the vegetation variation and its driving factors in global drylands including the dry subhumid, semi-arid,arid and hyper-arid areas. In this study, the long-term satellite data of GIMMS3g NDVI during the period of 1982 - 2012 and the precipitation and temperature data were used to illustrate the spatiotemperal variation of vegetation and its response to climate change and non-climate factors in drylands. The results are as follows: ① NDVI of vegetation in global drylands increased significantly (P < 0.001) with a rate of 0.000 5·a~(-1),which was slightly lower than that of global vegetation. The area proportions of global drylands with the significant NDVI increase and decrease to global vegetated areas with significant NDVI trends were 27.0% and 7.7% respectively. The largest areas of dryland regions with the significant vegetation degeneration occurred in semi-arid areas; ② Precipitation was the dominant factor affecting the change of vegetation in global drylands,expecially in arid and semi-arid areas,and its influence was slighter in dry subhumid and hyper-arid areas; ③ Because of the different climatic and geographic conditions and human factors, the change of vegetation in drylands was different from different regions. For example, the vegetation was improved in south Australia because of the effect of seasonal precipitation,but it was in a degeneration trend in South America and Eurasia due to human activities.