With the development of computer and space technologies, 3S technologies became an important mean on geographical research. And using these technologies on spatialization of population data also became a hot topic at home and abroad. However, the present researches were more on large-scale regions, like global scale, nation scale and province scale regions, and less on small-scale regions. Meanwhile, there were restricted on administrative region field and less on natural field, like river basin, natural landscape area and so on. Taking the Meijiang river basin of Jiangxi province as the example, this paper explored the population data spatialization method of the small river basin which is based on the spatial analysis technique of GIS and multi-source data fusion technique. In order to make the result more accurate and according to the characteristics of small basin, we selected terrain, roads and rivers as the main influencing factors. Settlements were selected as the indicative factor to ref