The microstructure, immersion corrosion behaviour in simulated body fluid and mechanical properties of Zn-1.2Cu-1.2Mg-xGd (x=0, 0.1, 0.25, 0.5, wt%) alloys were studied. The results show that the microstructure of zinc alloy is mainly composed of Zn solid solution and Mg₂Zn₁₁ intermetallic compound. When Gd addition content is 0.5wt%, the GdZn₁₂ intermetallic compound appears. The microhardness of zinc alloy increases with the increase of Gd addition content, and when the addition content of Gd is 0.5wt%, the microhardness reaches maximum, 1530 MPa. The tensile strength increases first and decreases afterwards, and when the Gd addition content is 0.25wt%, the zinc alloy has high tensile strength. Zinc alloy with 0.1wt% Gd addition content has the lowest corrosion rate.