The quasistatic properties and dynamic properties of 80W-Cu alloy in different loading conditions were studied, and the influence of stress state on mechanical properties of the alloy was analyzed. The results show that there exists an obvious asymmetry between compression and tensile properties of 80W-Cu alloy. In the compression process, 80W-Cu alloy exhibits good ductility while in the tensile process the material shows extremely poor ductility. Micro-analysis shows that the high W-W contiguity makes the failure easy to occur under tensile stress, which causes poor ductility of 80W-Cu alloy, while in the compression process, the whole deformation is well coordinated by the abruption of W skeleton and the plastic deformation of Cu phase, which results in good ductility of 80W-Cu alloy