A6061-T6 aluminum alloys is the main structure materials for vehicle manufacture. The train body had suffered severe corrosion damage under the effect of coastal,underground humidity and would affect the reliability of structures. This paper focused on the A6061-T6 aluminum alloy welded joints and study the weight loss,electric chemistry corrosion properties. The results showed that the rate of corrosion weight loss first showed a rapid increase,reaching a maximum at 14 th day,and then with the further extension of the corrosion time,the weight loss gradually decreased,showing a steady decline. The self corrosion potential had become positive with the order of Cl,-,、SO,4,2-,、NO,3,-,of base metals and weld but the self corrosion current had become small at the 5% mass fraction of different corrosion solution. The corrosion acceleration effect of SO,4,2-,was weaker than Cl-but higher than NO,3,-,.