Language identity and ethnic identity are interrelated.Language has various functions and thus plays different roles in identity construction.A national common language,for instance,functions as a common tool for communication and may construct a national identity,whereas dialects and ethnic languages can be more useful in constructing a cultural identity and for maintaining social rights.In addition,people who speak dialects or minority languages,and people who live in a multilingual environment,may show stronger language identity awareness than those who only speak the dominant languages,or those who use the languages of the majority population,and those who live in a monolingual environment.In this article,a number of studies are reviewed,including studies in the areas of national common language,regional dialects,and ethnic minority languages,and the related issues suchas language rights and cultural functions are discussed and problematized.Given the fact that the national language and ethnic languages have different social functions,for achieving language identity harmony we can improve the national language status with marketoriented policies,and protect the languages rights of the ethnic minority communities with non-market incentives.