Aquaculture production in artificial lakes is possible with a proper management of the lake ecosystem. Introduction of fish fingerlings are now a widespread approach in reservoir planning. Dorudzan reservoir is a main source of drinking water for the capital city of Shiraz, which is used for production of several species of cyprinid fishes by the fisheries department. Additionally, few species of native riverine fish are now established in the lake. Every species is supposed to have preferences in selecting different parts of the lake. To investigate possibility of this preference, fishes were sampled twice in winter 2010 and autumn 2011 in three sections of the reservoir, riverine, transitional, and lacustrine. Mesh sizes of 37, 57, and 120 mm were used for sampling. Total number of individuals in each station for all species was counted and their biometry (maximum standard length, fork length, maximum total length, and weight) were measured. Fish populations included Alburnus mossulensis, Capoeta aculeate, Capoeta damascina, Carasobarbus luteus, Carassius gibelio, Cyprinus carpio, and Hypophthalmichthys molitrix. Major parts of the lake showed different compositions of fish assemblages. All 7 species were observed in lacustrine, while 3 species Capoeta aculeate, apoeta damascina, and Cyprinus carpio were present at the transitional section. Riverine section hosted Alburnus mossulensis, Capoeta aculeate and Cyprinus carpio. This habitat preference can help a better utilization of the lake in aquaculture