Abstract: Spatial variability of soil salinity reflects the salinization and status of arable layer of soil. In order to observe the spatial distribution of soil salinity in different layers of arable land in fluvial landforms, the in-situ detecting method was adopted. The results showed that the soil salinity of each layer on the flooding plain had moderate variability and strong spatial autocorrelation, while the variability of soil salinity on river terrace was weak, the spatial autocorrelation of deeper layer was significant. The Kriging interpolation figure showed that the spatial distributions of salinity in the study areas were in the shape of stripe, concentric ring or uniform distribution. The salinity of surface layer on river terrace had a weak negative correlation with the gradient of sample sites. Terrain, hydrology and soil texture were the major factors that affected the spatial variability of soil salinity. The soil of these study areas was not salinization now, but salt accumulation of several measured sites on the flooding plain had higher risks of salinization, more attention should be paid to prevent the possible salinization.