Abstract: To grasp the spatial differentiation characteristics of soil nitrogen and phosphorus ecological stoichiometry and its main influencing factors in a small watershed in the black soil area of Northeast China was of great significance for rational fertilization application. This paper took the Haigouhe River Basin as an example, the spatial variability, distribution pattern and influencing factors of the ecological stoichiometry of soil nitrogen and phosphorus on the surface soil (0-20 cm) were analyzed by applying classical statistical, geostatistical model methods, and integrating "3S" technology. The results show that the mean of total nitrogen (TN) content, total phosphorus (TP) content and soil N to P ratio (N/P) were 2.60 g·kg^-1, 0.55 g·kg^-1 and 4.78, respectively, and the spatial variability of TN content, TP content and N/P were moderate, which were significantly affected by structural elements, e.g. terrain factors and parent materials. The TN, TP and soil N/P showed a stepwise change from east to west, a slight change from north to south, the changes were in good agreement with the change of inland deformation. There was a quite difference in TN content, TP content and N/P under different land use types, the TN content was higher in forestland than that in corn and rice land, while the TP content in forestland was lower than that in corn and rice land. The soil N/P was higher in the agriculture-pasture ecotone where was in the middle of the basin. The N/P was lower in cultivated land than that in other land in general. Cultivated land was also the important area of fertilization management and prevention and control of agricultural non-point source pollution in the agricultural production process. The accumulative effects of agricultural management measures, rural residential, road and other factors on agricultural production and spatial distribution of soil nutrients were more significant.