As the world becomes more globalized thanks to the fast development of the Internet, a national identity becomes more important than ever before. Based on this, the study searches for the identity of modern American architecture through exploring the influence of modem American fine arts on the contemporary architecture. It was found that the concepts and the attributes of modern American fine arts obviously transferred into the contemporary architecture. The main concept was elimination of any kind of illusion for maximization of reality, and it was rooted Into American culture, the way of life and thinking. With the concept, the attributes were divided into two extreme poles: materiality and morphology: the former was evolved from Abstract Expressionism and Post-Minimalism and transferred into Los Angeles Avant-Garde architecture; the latter was from Pop Art and transferred into Postmodern architecture and Pop Architecture.