Owing to the fact that the outer- wall paint,exposed to the weather,is subjected to following attacks,such as ultraviolet ray,heat,rainwater and dust deposit in the air,the protective and decorative actions of outer- wall paint are damaged,and eventually the paint loses its practical use.In this paper,due to the fact that the acid deposit injury is very serious in chongging region,the methods of weatherability test applied for outer- wall paint in the region,are studied.