Abstract: Taking fraction as analysis object, the crushing of granular soils is divided into three stages. Based on this, new concepts of discarding ratio R_k and weighted discarding ratio B_d are proposed for the crushing of a single fraction and granular soils as a whole respectively. And their theoretical computing methods are put forward based on the simplified hypothesis of geometric progressional distribution. By investigating the collected test data of particle crushing for 21 granular soil samples from references, it is found that the relationship between B_d and #x003c3;₃ is linear for different granular soils with varying values of #x003c3;₃ in research ranges. In addition, there exist significant turning points of slope in such linear relationship for most test results. Considering the combined effects of confining pressure, strength of mother rock and original grain composition, it is concluded that the variation of B_d is generalized for the particle breakage of limestone, breccia and sandstone. By sorting out the weighted discarding ratio B_d and the breakage factor B_g of the collected test results for different granular soil samples, it is indicated that the relationship between B_d and B_g is exponential. Finally, it is pointed out that the proposed quantitative method for the crushing of granular soils based on the discarding parameters has its own characteristics and advantages, which has broad research prospects.