<p>A series of ‘generalized axisymmetric compression’ tests on dense and loose sand were conducted via three-dimensional DEM (Discrete Element Method) simulations to investigate the state-dependent dilatancy behaviour through the critical state (CS) framework. The effects of stress path, initial confining pressure, and initial density state are explored. The critical state behaviour for both macroscopic and microscopic responses is examined. Dilatancy is quantified and investigated in terms of both dilatancy rate and dilation angle, respectively. Some existing stress-dilatancy models on dilatancy rate (original Cambridge model, modified Cambridge model, Rowe’s model, Li and Dafalias’s model, among others.) and on dilation angle (Bolton’s empirical equation) are examined, which are found to be only applicable to late shearing stages, but not to the initial shearing stages under ‘generalized axisymmetric compression’ conditions. A new stress-dilatancy model in terms of dilatancy rate, considering full shearing stages, is proposed based on the CS framework, which is validated by both the DEM simulation data and the laboratory data in the literature.</p>