A new bounding surface plasticity model considering the effect of anisotropy on the behavior of saturated soft clay under cyclic loading is proposed within the framework of critical state elastoplasticity. A non-associative flow rule and an internal variable reflecting the anisotropy of soil are introduced in the model. The initial anisotropy is depicted by the initial value of the internal variable and the evolution of anisotropy produced by cyclic loading is described by a rotational hardening rule with robust rationale and availability of model parameters. A radial mapping rule with the updated projection center and an interpolation function of plastic modulus associated with the length of the deviatoric plastic shear strain trajectory are adopted in the model to describe the fundamental behaviors including nonlinearity

hysteresis and strain accumulation of stress-strain responses of soft clays subjected to cyclic loads. The roles played by model parameters and their determinations are also explained. In particular

a rational method to calibrate the initial internal variable for describing anisotropy of specimens is developed. The validity of the new model is verified by comparing the predicted results with the cyclic triaxial test results under isotropically consolidated and anisotropically consolidated conditions for saturated soft clay.