In this work, the mechanical behavior of partially sintered ceramics under both tensile and compressive loadings was investigated by performing 3D discrete element method (DEM) simulations. The simulation results indicated that the failure of samples under tensile loading was dictated by the nucleation of crack, whereas for compressive loading it was linked to the coalescence of cracks. By monitoring the time sequence of bond breakage and its failure mode, it was found that for tensile loading the dominate failure mode of bond was tensile fracture, whereas for compressive loading it was shear fracture. The fracture strength of sample was closely related to the critical tensile (?c,t) and shear (?c,s) fracture strengths of bond. As to the partially sintered alumina ceramics considered in this work, it was found that the predicted tensile and compressive fracture strengths can both be in quantitative agreement with experimental data. The simulation results indicated that the influence of the distribution of bond strength on the compressive fracture strength of sample was minor. While for tensile fracture strength, it depended on the type of distribution: for Gaussian distribution, the strength of sample only weakly depends on the distribution width, whereas for uniform distribution, the strength of sample decreases notably with the increase of distribution width.