This paper takes the "roof" of Chinese classical architecture as the research object, and taking the angle of "design aesthetics" as the breakthrough point. Through the analysis of the rationality and sensibility of the roof plastic art, reveal the dual artistic features of "roof" shape which is having "beauty of shape" and "beauty of idea". The content of the argument making a comprehensive analysis is mainly from the "rational method of roof structure", "expressing the emotional feeling", and "beauty of implied meaning" and many