Abstract: Calcareous sand has the characteristics of high porosity, low strength, and easy breakage. Meanwhile, calcareous sand also has the possibility of liquefaction due to the action of vibration loads such as waves and earthquakes. In order to explore the relationship between particle breakage and liquefaction resistance of calcareous sand, triaxial tests were carried out on calcareous sand obtained from Yongxing Island, South China Sea. Firstly, the calcareous sand was crushed by an impact device in order to obtain samples with different relative breakage rates(Br), and then liquefaction tests were carried out on the original samples and the samples with different crushing degrees by a triaxial apparatus. The results show that under the same confining pressure and relative density, the liquefaction resistance of calcareous(CRR)sand decreases with the increasing relative crushing rate, but the decreasing rate reduces with the relative crushing rate. On the other hand, the increase of the relative density will weaken the influence of the particle breakage on the liquefaction resistance of calcareous sand. Finally, a mathematical relationship between Br and CRR was established to quantitatively evaluate the influence of the particle breakage on the liquefaction resistance of calcareous sand.