Abstract: In order to study the dynamic constitutive relation of frozen soil, a phenomenological constitutive model for its damage due to impact load was developed in this paper. Under impact load, the strength of frozen soil decreases because of crack extension and grain redistribution. With the assumption that the frozen soil consists of both viscous and damaged bodies, the strength theory and the equivalent inclusion theory of composite materials were utilized to study the dynamic constitutive relation. The Hopkinson pressure bar (SHPB) was used to test and obtain the dynamic mechanics response of the frozen soil at different strain rates. The results show that the frozen soil is of the rate sensitivity. Compared theoretical results with dynamic experimental results, it is found that the method of establishing the dynamic constitutive model is feasible and the proposed model can predict the deformation behavior of the frozen soil well.