Spatial variation of soil salinity and sodicity is a typical characteristic of Songnen Plain grasslands in northeast China. Best management practices and grassland productivity improvement require further understanding of the relationships among the causal factors at field scale. A field soil survey for the interactions among salinity, microtopography, and vegetation was conducted on a 2.8 hectare saline sodic grassland at Da’an Sodic Land Experimental Station, Chinese Academy of Sciences, northeast China. Salinity of the soil decreases by depth increment with Na⁺ and HCO₃ˉ as the dominant ions. Soil salinity and sodicity parameters measured include pH, electrical conductivity for 1 to 5 soil-water extracts (EC_1:5), apparent electrical conductivity (EC_a), sodium adsorption ratio, and exchangeable sodium percentage. Soil salinity is in an order of slope > mound > depression for microtopography and soil under S. corniculata community is in severe salinity, while there is no significant difference under P. australis-A. mongolica and P. australis communities. The water and salt regime in various microtopographical conditions also is discussed.