Overheating has a pronounced effect on the thermal stability and mechanical properties of Cu36Zr48Ag8Al8 bulk metallic glass. Higher overheated temperature can enhance the thermal stability of bulk amorphous alloys, corresponding to higher specific-heat capacity and smaller initial defect concentration. Bulk amorphous alloys exhibit good compressive plasticity at small overheated levels, whereas the compressive fracture strength and microhardness show a significant increase followed by a slight decrease. The mechanical properties of bulk metallic glasses fabricated by different casting process are influenced by the interaction of the free volume and residual stresses