Annotation:::: The paper provides a comprehensive study of natural geography related to resettlement of mountain migrants in Yunnan province, and explores ways of how to better use mountain area and flatland. Using methods of empirical study and on-site investigation, different ways of dividing mountain regions from flatland regions were assessed using DEM-based programmes of ArcGIS and ERDAS to provide the scientific basis for adjustment of agricultural structures, development of reserve arable land resources, and eco-migrant settlement in Yunnan. According to their results, the composition of Yunnan province’s total area is as follows: flatland region covers 6.72% – 8.19%; semi-mountain region covers 22.6% – 25.38%; high cold mountain region cover 15.61% – 15.78%; and mountain region covers 52.29％– 53.77%. Those regions are mainly distributed over the eastern Yunnan plateau, southwestern and southern river valley areas, the surrounding area of flatland, Hengduan Mountain, and other parts of the province.This paper is part of the National Natural S
