Abstract: The offshore wind turbine structure has strict control criteria of the tilt and the resonant frequency of the foundation, while the small strain stiffness of the marine soils plays an important role in these properties. The hardening strain model with small strain (HSS) can appropriately consider the nonlinear stiffness degradation in the small strain range. The laboratory oedometer, GDS triaxial and bender element tests are carried out to determine the HSS model parameters for typical marine soft soils in Yangjiang, Guangdong Province. The parameters include the strength parameters c', φ', stiffness parameters$E_{\text{oed}}^{\text{ref}}$,$E_{\text{50}}^{\text{ref}}$,$E_{\text{ur}}^{\text{ref}}$, failure ratio R_f and small strain shear stiffness$G_{\text{0}}^{\text{ref}}$ at a reference stress. The test results are analzsed, and the relationship between these parameters and void ratio of the soils is proposed. It provides useful suggestions for determining the HSS model parameters of the marine soft soils in Yangjiang.