The importance of fisheries in the economy of the country is very high. It supplies food, medicinal, fodder and technical products. The first place is occupied by fish food products, which are important sources of proteins in the population, fat, vitamins and mineral salts. From marine vegetation a number of medicinal products are produced: iodine, mannitol and others. Economic efficiency is the main category of the market economy, which is related to the achievement of the ultimate goal of development of economic activity. Increasing the effectiveness of the fishing industry is to increase economic results in the process of using available limited resources. The importance of economic analysis is emphasized since it provides a basis not only in the decision making of the individual farmer, but also in the formulation of aquaculture policies. Thus, greater attention should be focused on the improvement of economic data for analysis. The purpose of the article is to study the theory of efficiency of fish industry.