The mechanical properties and electrical conductivity of Cu 100Àx Zr x (x ¼ 0{8 at%) alloys were examined, whereby the alloys were prepared by casting levitation-melted alloys into a pure copper die and then subsequently cold rolled to a thickness of 200 mm except for the alloys where x ¼ 7 and 8. The ultimate tensile strength ( UTS ), 0.2% proof strength ( 0:2 ) and Vickers hardness (H V ) of the prepared Cu 100Àx Zr x alloys increase linearly with x, elongation " P is almost independent of x and the electric conductivity (%IACS) decreases when the Zr concentration x increases. The highest values of UTS , 0:2 , " P and H V for the Cu 100Àx Zr x alloys are 1200 MPa, 800 MPa, 3% and 290, respectively, at x ¼ 6 and its electrical conductivity is 35%IACS.