In this paper, the dilatancy rate of a sand in the triaxial drained test was proposed to evaluate the liquefaction potential of the sand. Based on laboratory test data, the relationship between the dilatancy rate and the liquefaction resistance was developed. The effects of most of the factors affecting the liquefaction potential, such as relative density, confining pressure, overconsolidation, period of sustained loading, and fines content, are all considered in this relationship. It can be applied to various sands of hard and bulky particles. However, the effect of particle crushing should be taken into account for sands of flaky and friable particles.