In order to discuss the air pollution influence on the surface weathering of carved stone in Nanxiangtang area, all indexes of the air in recent years acquired from four monitoring stations near the rock-cut building were analyzed, and weathering crusts were wathed by SEM. Based on these analyses, a formation mechanism of weathering was concluded that air pollution was the main factor emhancing weathering process. As a result, keeping the air from pollution is to be the main step to protect the carved stones in Nanxiangtang.