Character of population distribution is one of the focuses studied by urban geography. Using the fifth national census data as basic data and using areal interpolation method, this paper analyzes character of urban population distribution of Shenyang City, Northeast China, in terms of three aspects of statistical character, spatial auto-correlation and spatial structure. Furthermore, this research analyzes the factors affecting the population distribution of the city. The main conclusions include: 1) There is an obvious structure character of population distribution in the grid with a grain of 300m, which is appropriate scale when researching population distribution in Shenyang City. 2) Urban population distribution has the character of assembling while population density distribution takes on variability in Shenyang City. 3)Population density distribution shows spatial auto-correlation within 7.36km. Spatial heterogeneity of population density is low. 4) Urban center, population distribution barycenter and population density maximum points separate each other.Population density distribution has multi-cores character. 5) Layout of governments, primary schools, middle schools,colleges, hospitals and marketplaces affects population distribution directly. With the increase of distance to these factors,population density decreases as logarithm.