Abstract: The study on dynamic characteristics of earth material has guiding meanings to seismic design of earth rock dams.In this study, aiming at clay core wall of an abroad hydropower station, a series of cyclic drainage triaxial tests on the soft clay under anisotropic consolidation was conducted.The effects of consolidation ratio Kc,effective confining pressure σ′c and cyclic shear strain amplitude γa on soil volumetric deformation εvd were investigated.The results show that the εvd is linearly related to γa under cyclic loading with small magnitude strain, and the development of εvd/γa under the same consolidation conditions are in good agreement.The influences from Kc,and σ′c on the εvd is associated with the soil microstructure.The larger the σ′c and Kc are, the smaller the εvd will be under the same vibration number.The test result demonstrates that the incremental volume variation model proposed by Martin adequately describes the volumetric deformation of the soft clay in this test.