The mechanism of desertification has always been the hotspot of academic research.The Hexi region,which is located in the transitional zone from the Qinghai-Tibet Plateau to the arid area in Northwestern China,is a key region for construction of the Belt and Road Initiative.Hexi area is the bridge of material and cultural interaction between East and West China during historical period,meanwhile,Hexi is also one of the areas with the most serious desertification in China,the worsening desertification has seriously affected the development of local economy and culture and threatened the smooth implementation of the Belt and Road Initiative.So,grasping the causes and evolution mechanisms of desertification clearly in Hexi area will have great significance in formulating desertification control strategies and controlling desert expansion.The ecology and environment in Hexi area is very sensitive to the intensity of human activities and to climate change,a large number of studies have shown that desertification was controlled by climate change before 3 ka,and then human activities gradually became the dominant factor of desertification after 3 ka.But the way in which human activities affect the desertification process has not been reported.Based on coupling with histories of desertification,warfare,variation of the population and climatic background,this paper analyzed the mechanism of desertification over the past 1 ka.The following results were obtained:(1) During the latest 1 ka,desertification in the Hexi region happened in intervals of 0.91 ka,0.74 ka,0.68 ka,0.44 ka,0.32,0.24 ka,0.18-0.12 ka and <0.1 ka.(2) Desertification sensitively responded to intensified human activities except that happened at around 0.32 ka as a consequence of low precipitation.(3) Desertification during the recent 200 years is a response to rapid growth of human population.Main innovation points of this paper include as follows:(1) There were 8 desertification processes occurred in the Hexi area during the latest 1 ka.(2) the wars occurred in the region was regarded as a strong human activity on desertification in the paper.