In order to investigate the effect of the heterogeneity on creep behavior of asphalt concrete, three dimensional(3D) simulation of uniaxial creep test was performed using discrete element method. The 3D discrete element(DE) digital specimen composed of coarse aggregates, asphalt mastic and air voids was generated. The corresponding micromechanical models among the interactions of microscale components of digital specimen were assigned. The 3D DE model was also verified with laboratory measurements. On the basis of the 3D DE model, the Weibull distribution of coarse aggregate stiffness and the microscale viscoelastic parameters of asphalt mastic were assumed in DE model to investigate the effect of the heterogeneity of coarse aggregates and asphalt mastic on creep behavior of asphalt concrete(AC). The results show that the creep strain of AC decreases with the increasing homogeneity, and decreases faster with the increasing homogeneity of coarse aggregates than with that of asphalt mastic. The creep behavior of AC is more sensitive to the heterogeneity of coarse aggregates. The creep strain of AC in which the aggregate stiffness distributes uniformly decreases by 49% compared to that of AC in which the coarse aggregate homogeneity is lower (homogeneity m=1.0). Therefore, more attention should be paid to the homogeneity of coarse aggregates in choosing the component materials of AC. The coarse aggregates of stable homogeneity should be used, and those from different origins should not be blended.