Its understanding of ethnic groups was based on Sun Yat-sen\'s idea of nationalism and aimed at realizing political interests with its clan theories ignoring the historical and cultural tradition of the minority groups.

Written from the definition and change of the identity concept, this paper introduces western researchers?studies on the development of ethnic identity, ethnic identity and mental health, ethnic identity and acculturation, and ethnic identity and personality development, etc, and summarizes some study strategies of ethnic identity.

After a survey in 2116 adolescents in Southern Xinjiang,the paper reveals that the adolescents in Southern Xinjiang are more positive in national identity than in ethnic identity,the ratio in national identity and ethnic identity changes as the cognitive structure of adolescents develops,not following a straight line.

Cultural identity is the basic premise of national identity and ethnic identity,national and ethnic identity is maintained and the basis for the realization of national reunification,and ultimately,national cultural identity has become an important foundation for the peaceful reunification.

On the Opening-up and Reform and the national identity of China

Promoting harmonious development between ethnic groups and the country hence become the issue of solving the problem between ethnic recognition and national recognition.

In the long developmental history,each ethnic group developed their ethnic recognition but compared with the ethnic inner recognition,the national recognition of China by each ethnic group is not that smooth.

Ethnic recognition is an inevitable outcome of history.