Dilatancy is a key behavior of soils that affects their strength and deformation. A study on coarse-grained soils using large-scale triaxial tests found that the stress-strain curve shows softening behavior when the ratio of volumetric strain to axial strain decreases to a minimum value. The soil's dilatancy and strength peak at this point. If the ratio decreases continuously, the stress-strain curve behaves as hardening. The trend of volumetric strain depends on the soil's dilatancy and compressibility. When dilatancy rate is higher than compression rate, the soil shows stress softening. Otherwise, it exhibits hardening behavior. Understanding dilatancy in coarse-grained soils is crucial for predicting their strength and deformation.