Probiotics are microorganisms which added to the diet in order to improve the health of the host. In the present study, the effects of probiotic, PROTEXIN® on growth, survive and hematological parameters of Benii, Mesopotamichthys sharpeyi (15. 62± 0. 45g) were investigated in Fish Propagation and Rearing Center, Islamic Azad University, Ahvaz. To this aim, 360 fish were assigned to 12 experimental tanks as 3 experimental treatments including T1: 0. 5% Protoxin® , T2: 1% Protoxin® and T3: 1. 5% Protoxin® (triplicate) for 60 days. Also, one group fed with Protoxin-free diet was considered as control. The results of the present study showed that probiotic containing diets especially those fed with 1. 5% Protoxin® (T3) increases weight, specific growth rate, and feed and protein efficiency and also decreases feed conversion ratio. Survival rate values showed no significant differences between experimental groups. The hematological parameters including hemoglobin concentration, the number of monocytes, heterophils and basophils were higher in experimental treatments than control. In contrast, the numbers of red blood and with blood cells were lower in probiotic received groups compared to control group. The Results showed that Protoxin® (especially T3) improve weight index, increase weight, specific growth rate (SGR), protein efficiency, feed efficiency and condition factor but decrease feed conversion ratio (FCR) of Bunni. In conclusion, results suggest that Protoxin® improve growth of Benni.