Abstract: This paper presents a critical discourse analysis and a comparative study of the Chinese and American white papers on national defense from 2002 to 2008. It finds that China and U.S. differ greatly in their choice of words, classification, modality and macrotextual structure in constructing their respective national identities. The very national identity the Chinese government intends to construct is that of China as a peaceloving and developmentpursuing country that highly cherishes cooperation and avoids confrontation, while the U.S. government portrays the U.S. as a superior country with a mission. This difference can be attributed to the culture of harmony in China and the mission mentality deeply rooted in America.