Abstract: Two kinds of aluminium alloy brazing solders, LA₂, LA₃, and two kinds of zinc alloy solders, LZ₁, LZ₂, for Al-Cu joint welding are developed. Among the four solders the experiments show: the LZ₁ solder is a standard solder for comparative analysis; the LZ₂ is an ideal solder suitable for Al-Cu joint welding. The results were obtained through testing the performance and anaylzing the structure and the components of both the solder itself and the brazing joint.