Summary: The cyclic behavior of soil-structure interface can be very important in dynamic problems. The cyclic behavior of soil-structure interface may be nonlinear, which includes hysteresis, hardening, degradation, and particle breakage. The breakage of granular soil particles during shearing of granular soil-structure interface is associated with cyclic degradation and can be critical to the dynamic behavior of soil-structure system. The critical state soil mechanics concept formerly used to simulate the nonlinear monotonic behavior of granular soil-structure interface was modified and extended to describe the cyclic behavior, especially soil-particle breakage and degradation during cyclic shearing. Soil-particle breakage was assumed to relate to the energy consumption during cyclic shearing and the critical state line of the soil-structure interface was assumed to translate with the consumption of shearing energy during cyclic shearing as the threshold value is attained. The model was formulated in the framework of generalized plasticity and is capable of describing the salient features of granular soil – structure interface under cyclic loading. Most of the model parameters have straightforward physical meanings and are calibrated using monotonic or cyclic interface test results. The proposed model was calibrated and validated against published test results. The dependency of interface behavior on stress path and cyclic degradation can be successfully described by the proposed model.