Sevan national park is a state non- profit, ecological, scientific-research organization, which is founded at 14 March, 1978 to protect Lake Sevan and the surrounding areas. The objectives are: the conservation of natural ecosystems , landscape varieties and biodiversity, scientific researches of natural heritage, protection , regeneration , recovery, inventory, monitoring, observation and the utilization of natural resources. SNP is located in the northeastern part of the country and is surrounded by five mountain ranges. The lake has a tectonic origin and the surrounding mountain ranges were formed as a result of active volcanic activity in the Triassic period. The Park includes the surface area of the lake and some coastal areas released from water up to the road running around the lake. Lake Sevan is the biggest and highest freshwater lake in the Southern Caucasus. Fish species in Lake Sevan are represented with 3 families.The target species of our project- Sevan Trout (Salmo ischchan Kessler 1877) belongs to Salmonidae family,which includes Sevan Trout, with its four ecological races (subspecies). The two subspecies of it became extinct in the world: Winter ischchan- Salmo ischchan ischchan and Bojak- Salmo ischchan danilewskii.These subspecies are generative lacustrine subspecies, which lived only in the Lake Sevan and were not recorded outside of Armenia. Summer bakhtak- Salmo ischchan aestivalis Fortunatov and Gegharkuni- Salmo ischchan gegarkuni are endangered endemic subspecies of limited distribution. Summerbakhtak also lives only in Lake Sevan, but gegharkuni was acclimatized in the Lake Issyk Kul. The principal factors of extinction are shoaling of rivers with spawning grounds, water pollution, dry out of lake spawning grounds, caused by the man-made lowering of lake water level, deterioration of natural conditions and poaching. We will focus the efforts of the project on the assessment of Sevan trout with it's 2 subspecies.