With important transit corridors and easy access to Persian Gulf and Caspian Sea region, Iran is a short, affordable, accessible, and safe transit route for transporting grains to the target markets in Persian Gulf region and South Africa countries. In this study, required data for indicators and potentials of Southern Commercial Ports of Iran engaged in transit of grains is gathered using the knowledge and experience of data-collection experts and then they value these indicators using questionnaires filled by statistical population of study. Then, ports which have necessary potentials to operate as grain terminal are determined by SPSS Software. Afterward, importance and priority level of each indicator and their effects on ports determined using Expert Choice Software. SPSS results indicated that ports of Imam Khomeini, Bandar Abbas, and Chabahar have the required potential to operate as a grain terminal and results of Expert Choice reveal that the importance of rail and road networks, storage capacity, grain dock, required equipments, and distance to northern ports is respectively 35.6%, 26.9%, 18.6%, 11.1%, and 7.9%. And the absorption rate of indicators affect the transit of grain in Port of Imam Khomeini, Bandar Abbas, Chabahar, Khoramshahr, and Bushehr is respectively 46.5%, 27%, 9.9%, 9.5%, and 7.1%. Therefore, Port of Imam Khomeini is the best choice for operate as grain terminal.