Abstract: The evolution of multi-size particle materials considering particle crushing is studied considering the evolution of single-size ones. A two-parameter Weibull distribution function is introduced to describe the crushing state of single-size particles. Besides, the concept of effective breaking probability of multi-size particles is proposed. Based on these, a Markov chain model is established to describe the evolution of multi-size particles considering particle crushing. The proposed model is verified by selecting the experimental data under different geotechnical materials, test conditions and particle sizes. The results indicate that the proposed model can approximately describe the evolution of geotechnical materials considering particle crushing.