The microstructure and corrosion resistance of AA5052/304 SS rotary friction welded joints before and after heat treatment was studied. The results show that the distribution characteristics of intermetallic compounds along the radial direction in the as-welded joint were different, due to the inhomogeneity of heat generation and pressure at the interface. No intermetallic compound formed at the center but distributed continuously at 0.25 R, 0.5 R, and 0.75 R. Inhomogeneity of corrosion resistance in different areas of the joint was observed, and the corrosion resistance was ranked as: 0.75 R>0.5 R>Center>0.25 R. After heat treatment at 250 ℃/20 min, the residual stress in the joint was released, the microstructure was homogenized, and the radial inhomogeneity of the corrosion resistance disappeared.