For developing bulk metallic glasses with high glass forming ability (GFA) and good mechanical properties, Cu 922x Zr x Al 8 (x535-65 at-%) alloys have been studied by means of tilt mould casting method. The largest glassy rod with a critical diameter of 18 mm in this alloy series was obtained for Cu 42 Zr 50 Al 8 alloy. The Hruby factor is appropriate for evaluating GFA in the cast Zr-Cu-Al bulk glassy alloy. The bulk metallic glasses with high GFA exhibit good mechanical properties, i.e. compressive fracture strength of 1783-2240 MPa, Young's modulus of 90-123 GPa and plastic strain of 0-0?73%.