A series of triaxial tests were conducted to investigate the characteristics of the critical state loci (CSLs) of original and pre-crushed sands. The results of the original sand showed that the CSL was divided into two segments by a particle breakage reference stress (0.7 MPa) not only in the e-logp' plane but also in the q-p' plane. The results from the pre-crushed sands revealed that particle breakage resulted in a downward translation and an anticlockwise rotation of the CSL in the e-logp' plane. However, in the q-p' plane, all the critical state points were on the initial CSL, but with different evolutions against particle breakage for drained and undrained tests.