Abstract: Based on the data of the fifth, sixth and seventh population censuses in Yunnan Province, this paper analyzes the spatial characteristics and influencing factors of population contraction in Yunnan province at the county and town spatial scales for the first time. The results are as follows: (1) Since 2000, the centralization trend of population distribution has been strengthened, and the differentiation of population growth and contraction region has become more and more obvious. (2) Compared with 2000-2010, the areas with the shrinking population in 2010-2020 doesn't only show a significant trend of expansion at county and town scales, but also showed an increasingly severe degree of contraction. (3) According to the spatial distribution of population shrinking regions at the town scale from 2010 to 2020, the population change of the whole province presents an obvious feature of 'core growth and marginal contraction'. At present, county-level cities (towns) are the main growth point of population in each region of the province. (4) According to the results of regression analysis, compared with the level of regional economic development, the supply level of public service facilities represented by education and medical care plays a more prominent role in population agglomeration, which may become the key to affecting population migration between regions in the future.