The swelling pressure induced by expansive soils is considered a valuable parameter for the design of structures resting on these soils. It must be estimated in order to prevent damage to these structures and to design safe shallow foundations. In the recent research studies, the swelling pressure of expansive soil was predicted using the soil water characteristics curve SWCC. The present work investigates the interplay of the SWCC with the swelling pressure of expansive soil. The ABAQUS software was implemented in order to perform a coupled analysis of the expansive soil behavior. Published properties of the Regina expansive soil was used in order to validate the present numerical model. The validated numerical model showed good agreement with the published data of the Regina clay. The effect of the SWCC shape on the swelling pressure was thoroughly studied. The present results show a significant effect of the SWCC shape on the swelling pressure of the expansive soils.