The corrosion behavior of different regions of AA2219-T87 aluminum alloys after self-reacting friction stir welding was investigated through the electrochemical corrosion and immersion corrosion tests. The results show that the weld nugget zone (WNZ) has the optimal corrosion resistance, while the base material shows the worst corrosion resistance. In the base material, the volume fraction of precipitated phase is the largest. The closer the area to the nugget center, the more the dissolving precipitated phase. WNZ is composed of fine equiaxed grains with a small amount of θ phase.