Based on the multi-objective regional geochemical survey data, soil arsenic (As) content in the core area of black soil in Songnen Plain was analyzed by means of geostatistical analysis and GIS spatial analysis, and soil As pollution was evaluated by means of geo-accumulation index and potential ecological risk index. The results showed that soil As content ranged from 2.1 to 107.7 mg/kg with the average of 9.09 mg/kg, slightly higher than the corresponding background value of soil As. The high-value clustering area of soil As was mainly distributed in the upper reaches of Hulan River, while the low-value clustering area was mainly distributed in the lower reaches of Hulan River and Songhua River basin. Soil As content had a strong spatial autocorrelation, which is dominated by structural variation. The spatial distribution of soil As was significantly affected by factors such as soil parent material and water system. 98.52% or 99.88% of the study areas were pollution-free or with low potential ecological risk. It is suggested to slow down the increase of soil As content by improving agricultural cultivation methods, adjusting planting structure, reducing the use of pesticides and chemical fertilizers and other human factors.