Nationd identity can make some extensive influences to the practice of democracy in our country because the condition of differentiating national identity of people was made by the separation and the combination of the provincial origins, ethnicity, special reasons of history, factors of geography and the condition of China and Taiwan's interchange. The main question of this essay is: what are the conditions and attitudes of national identity of high school students who will soon become citizens. This essay started to account the present condition of national identity of high school students and what kind of factors that influence their national identity. First, it pointed to the meaning of national identity to clear the relative conceptions of studying. Then, it told how to measure the national identity by explaining the contents of questionnaire which related identity with nationalities, institutions, culture and so on. After that, it also presented the correlative factors of high school students' national identity and other relative by through getting and analyzing the materials about high school students' national identity. Finally, it made the conclusions and suggestions according to the findings of the study.