The author focuses on figuring out the changes in National President, Head of State institution, representing the nation in internal and external affairs in the 1946, 1959, 1980 and 1992 Constitutions. On the basis, the author suggest changing and completing the National President in the light of Party's XI Congress, on all aspects of position, role, power and obligation of the National President in the relationship with the National Assembly, the Government, the juridical agency, in order to fully function the National President as Head of State, representing the State in internal as well as external affairs and uniting armed forces.