Mariculture of trout fish in cage, which is a new approach of Iranian fisheries organization was followed by the last decade draining years and estimation limitation of fresh water fish production in Iran, harvested more than 2700 MT. of trout fish which is the successful choice of cage cultured fish species in three northern provinces - Caspian Sea. Final costs of fish production affected by different financial parameters such as fixed and current investments, in cage condition determined using industrial cost accounting or final production cost. In order to obtain final costs of each kg trout fish cultured in cages of Mazandaran coastal water, questionnaire from 5 trout fish cages were gathered during 2016 in that province. All data and costs are based on a cage with 15 MT capacities. Overall, initial fish biomass for releasing to the cage with the highest costs(41%) of total costs, followed by feed 37%, maintenance and 5 years amortization fixed investment (10%), Insurance(5%) and labor costs(0.018%) are the main factors final costs of the cage fish production. In this study this final production cost of one Kg fish cultured in cages system of Mazandaran province was calculated 129764 , which is 10 % lower than the price of fish cultured in raceway system(142740 Rials).