Abstract: With the development of urbanization and industrialization, many engineering problems about unsaturated soils are often encountered in practical projects. Engineering accidents related to unsaturated soils have also appeared in highway and railway projects, causing huge economic losses and casualties. Firstly, the fitting results of three SWCC equations (van Genuchten equation, Fredlund-Xing equation and Brooks-Corey equation) on the test results of different types of soils (clay, silt and sand) are studied. Secondly, in order to analyze the fitting effect of each SWCC equation for the dependency of the initial dry density, the variations of model parameters with the initial void ratio of soils in each equation are discussed. Finally, a prediction method for SWCC considering the influence of the initial dry density is proposed, which assumes a linear relationship between the initial void ratio and the saturation under the same suction. This method is verified by the comparison between the predicted and test results.