Via a series of swelling tests conducted on consolidation apparatus, the vertical swelling pressure with the deformation of remolded expansive soils was studied. According to the tests results, it is concluded that: the vertical swelling pressure is remarkably decreased with the increase of small swelling strain; the swelling pressure and dry density, initial moisture content and swelling strain present exponential relations. With the help of multivariate regression analysis, fitted regression equation of swelling force is found.