Effects of a small amount addition of Cr on glass-forming ability (GFA) and mechanical properties of Cu-Zr-Al bulk metallic glass were investigated. The GFA of (Cu46Zr46Al8)(100-x) Cr (x) (x = 0, 0.25, 0.5, 0.75, and 1 at%) alloys tends to decrease with the increasing Cr content. A good correlation between the GFA and the temperature interval of supercooled liquid region Delta T (x) or parameter gamma exists in these alloys. Addition of an appropriate amount of Cr can significantly improve the plasticity of the alloys. The bulk metallic glass with x = 0.5 exhibits promising mechanical properties with high fracture strength of 1870 MPa and obvious plastic strain of 2.23%.