Through large numbers of geotechnical tests

the correlativity between liquidity index and natural water content

natural void ration

natural density

modulus of compressibility

coefficient of compressibilty

cohesion of silty clay in the subgrade of Su-Tong Bridge Engineering at lower reaches of the Yangtze River was studied

regression equations were given

and the comparison of correlativity curves with other areas in China was also presented. It was found that the correlativity between liquidity index and natural water content

natural void ration

natural density

coefficient of compressibilty was linear

and the correlativity coefficients were over 0.92; the correlativity between liquid index and modulus of compressibility

cohesion is exponential

and the correlativity coefficients were over 0.87; there were better comparability between regression curves of silty clay in Su-Tong Bridge subgrade and regression curves of silty clay in other areas’ subgrade. The following conclusions can be drawn that these regression equations in this paper can provide important reference for silty clay in analogous subgrade.