Abstract: Soil pH is an important factor affecting the chemical and biological properties of soil. It also has an important impact on land productivity. To learn about the variation of soil pH in Xingkai Lake Plain in recent years, on the basis of the second national soil survey and soil pH data of 2019, the spatial statistics is used to analyze the spatiotemporal variation characteristics of soil pH in the study area over the past 30 years. The results show that the soil pH is generally declining, but does not vary greatly(±0.5 to ±1). In terms of land use types, the soil pH of cultivated land show a downward trend, while that in the western forest area remains unchanged or increases slightly. Among the 4 main soil types in Xingkai Lake Plain, except for dark brown soil, the other three are all falling in average pH values during the past 30 years. Therefore, it is necessary to conduct multi-factor and quantitative analysis to further clarify the specific causes of soil pH variation in the study area.