Abstract: This paper researchs the pattern of regional population spatial structure evolution and its influencing factors,which is based on the census and statistics data since the reform and opening up, taking Xinyang in central less-developed hilly area as an example, using GIS technology on different scales.The results show that:① The population spatial distribution of Xinyang city has significant regional differences. On the regional scale, the population spatial distribution has obvious gradient difference from southwest to northeast. At the county scale, the population of highly populated areas decreases gradually, and the population of low-density areas remains basically the same, with obvious population differences. On regional scale, the population density in the southern and western part of mountains is low, the population density in the central part of hills and downlands is medium, the population density in the northern part of Huanghuai Plains is high.The population center of gravity is always located in the geometric center of the northeast and the population gradually gathered from the east to the west. ② There are many factors influencing the population spatial pattern of Xinyang.Natural environment determines the spatial distribution pattern of population.Economic development level is the main reason for the population change trend. Regional land use planning strategy plays an important role in guiding the spatial flow of population.

Key words: GIS, scale domain, population spatial structure, Xinyang