This study was conducted to identify different stocks of big marine catfish (Netuma thalassina) as the most dominant marine catfish species in Hormozgan waters using morphological features. 209 big catfish were caught in three different habitats of marine Catfish in Persian Gulf and Oman Sea including Bandar Abbas, Bandar Lengeh and Jask, and the left side and ventral profiler of all samples were photographed. A total of 12 landmarks on the lateral side and 11 landmarks on the ventral homolog were defined on pictures, and digitized by using software tpsDig. Body. Moreover 20 geometric distances between ten landmarks, 9 traditional morphometric features were analyzed using discriminant function analysis (DFA) in different areas. The results of CVA analysis in ventral view of head shape and lateral view according to Mhala Anubis intervals showed that Jask catfish population separated from other groups. Based on ventral view of head shape, the most displacement of landmark parts were related to the tip of the snout, length and width of the head in the Lengeh population which had a shorter head length, wider head and mouth rather than Bandar Abbas and Jask catfish population. The total mean of lateral view showed that the most displacement between landmark points were related to the tip of the operculum, the height of the body and caudal peduncle area. On the other words, Jask catfish population had a thinner body height and longer body length compared to other groups. The results of discriminant function analysis (DFA) classified in an average of 94.7% individuals in their original population. In conclusion, our results showed a high phenotypic variation in big catfish stocks in Iranian coasts of the Persian Gulf and Oman Sea.