Abstract: TIG welding technology for heterogeneous materials of high damping mangnese-corpper alloy and 40CrNiMoA gear steel was introduced, and analysis on properties of tension, impact, cold bending, fatigue, metallurgical structure, impact fracture appearance, micro-hardness and marine atmospheric corrosion resistance was performed. The results manifested that all properties of the welded joints could satisfy requirements after adopting suitable welding parameters and stress relief treatment following the welding; Metallurgical structure of the welding line was homogeneous, and the fracture appearance was ductile; The widths of heat-affected zones of GZ50 alloy side and 40CrNiMoA steel side were basically the same; The phrase forms and their proportions in heat-affected zone of GZ50 alloy side and the base material were different due to different heat action; In marine atmosphere, corrosion rate of 12-month was approximately 50% lower than that of 6-month.