Pakistan emerged as a "nation state". This newly born state faced the problem of national integration. The main cause for the failure of national integration was the lack of the implementation of the determining factors of provincial autonomy and social justice at the constitutional and political levels. This study elaborates the problem of national integration in Pakistan. The analytical framework focuses on the theories of "integration" and the concepts of "nation", and "nationalism". The political culture is binding force for the stability of a nation. Therefore, analysis of political culture and its significance in nation building is also covered. In addition to that, this study examines the provisions of the three constitutions regarding the provincial autonomy and social justice. In this respect the efforts and attitudes of the governments for the implementation of these factors and problems faced are also discussed.