People receive national identity by socialization and make it a part of their personality and utilize it in appropriate circumstances. Therefore the existence of national identity is obtained by education. Since the social system of education is considered as a unique Sub-System which has the effective power on recognition, affection and social behavior of the students, this important factor mainly takes place in social atmosphere known as school with the help of the process of becoming sociable. undoubtedly, national identity is completed in the process of sociability by social relation inside and outsideth groups. Thus, schools are social atmospheres in which a varity of relationships occur and affect the process of national identity completion.The theoretical framework of this research is a combination of thought from experts who have made the theories in the felid of social relationship in small education system, such as Habermas, Parsons, Coleman, Homans and Blau. The thought of Jenkins is considered in identity subjects. Because Jenkins regards the completion of national identity by social relationships during socializing process of inside and outside the groups.The method of research is survey and the means of collecting data is the questionnaire made by researcher which has been exploited from theoretical grounds. After investing of reliability and validity, the collection of data and essential expressions regarding questionnaire were made. Statistical group of third year high school and pre- university students of four areas in Shiraz city has been 470 sample people the selection of samples have been done by presumptive sampling and cluster method randomly.The results show that the national identitys of students are comparatively strong at the high level, Moreover, the students are at a high level in the field of national identity recognition, but they have achieved the least success in the field of behavior. Regarding national identity and its dimensions, social exchanging, affectional (intimate) and discourse relationships, they have positive effect respectively. However, power relationships have negative effects. Finally, as the amount of intimate (affection), exchanging and discourse relationship between personal at school and students at school increases, the national identity and its dimension will be strengthened.