The plan to build a railway, the first discussions of which were related to the Qajar period, was realized during the period of Reza Shah Pahlavi. The national railway was put into operation in 1317. This line of communication had various economic and social effects. Investigating these effects is considered one of the important topics in the field of contemporary Iranian studies. This research aims to investigate the economic and social effects of the national railway on the ports of Bushehr and Bandar Abbas in the first and second Pahlavi periods between 1304-1332; Therefore, the central question of this research is, what were the economic and social effects of the nationwide railway on Bushehr and Abbasi ports in the first and second Pahlavi periods? The main hypothesis of this research is that the operation of the national railway caused the relocation of commercial centers in the northern shores of the Persian Gulf. The findings of this research, based on historical data and descriptive-analytical method, show that after the operation of the national railway, the ports of Bushehr and Bandar Abbas have experienced relative stagnation compared to the ports of Khuzestan that were connected to this line of communication, and their superior position They lost economically. This rail line also indirectly led to insecurity, migration, population decrease for the studied ports.
Keywords: national railway, Persian Gulf, Bushehr, Bandar Abbas, Pahlavi period, economic and social effects.