This essay proves the significance for the research in American individualism from the respective analysis of the strong potential energy of the American cultrue,of the important role of individualism in the American ideological system and of the widespread and profound influence of western individualism on today's China.And in taking account of both theory and practice,history and reality,it interprets the meanings and manifestations of Amenican individualism and also furnishs a fresh proof that collectism be promoted and individualism be opposed in China today.