Objectives: This inquiry is intended to study the national identity situation and its effective factors in between high school students. A nation is a form of self-defined cultural and social community. Members of a "nation" share a common identity, and usually a common origin, in the sense of history, ancestry, parentage or descent. A nation extends across generations, and includes the dead as full members. Past events are framed in this context. The national identity refers both to the distinguishing features of the group, and to the individual's sense of belonging to it. A very wide range of criteria is used, with very different applications. Small differences in pronunciation may be enough to categorize someone as a member of another nation. On the other hand, two people may be separated by difference in personalities, belief systems, geographical locations, time and even spoken language yet regard themselves, and be seen by others, as members of the same nation. National identity is one of base that shape individual personality. National identity is answer to questions such “who” and “what” about self and his/her country. So national identity is personal define of self. National Identity creates personal commitment to country and social community. This is important among youth generation because in youth age establish individual personality. Therefore National Identity is one elements of youth’s personality. Method: This research studies the national identity situation and its effective factors in between high school students. Research sample is 400 students in Shiraz city. Research method is survey. National identity measured in eight dimensions includes social identity, geographical identity, historical identity, cultural identity, ethnical identity, linguistic and Literature identity, political identity and religious identity. National identity variable combined of these dimension. Independent variables include: belong feel to society, individualism, positive attitude to western countries, values gap with parent, schools curriculums, membership in social categories, social inequality feel, national identity Narrative and social- economic- political satisfaction. Findings: The study indicates that national identity rate in between 88 percent of students is high and medium and 22 percent of students have low national identity. National identity between girls and boys is not significant. However girls student have higher rate from boys in social, geographical and religious dimensions of national identity and boys have higher rate in ethnical identity. Results: Results show that the belong feel to society, positive attitude to western countries, political system legitimacy and individualism variables have significant effects on national identity. The Belong feel to society and political system legitimacy have positive effect on national identity and positive attitude to western countries and individualism have negative effect. A structural equation analysis (SEA) of data with Lisrel 8.53 indicates that major Constructive parts of national identity are geographical, cultural and historical dimensions.