Abstract: Expansive soil can not be directly used as the roadbed filler owing to its remarkable expansion and contraction properties. Based on a railway project, 3%, 5%, 7% dosage of the lime were incorporated in expansive soil,  the free swelling ratio of expansive soil improved between different contents and different ages, the shrinkage deformation and the shear strength parameters with variation were investigated. The results showed that: more than 3% dosage of the lime can effectively suppress the free swelling ratio of the expansive soil; more than 5% dosage of the lime can effectively suppress the cracks of wet and dry cycle inhibition in the development of expansive soil, which dramatically reduced each expansion and shrinkage deformation for the cycle of wet and dry, and ensured that the shear strength was not impaired.