Fish survey were undertaken during August 2015 to March 2016 to predict the taxonomic study of the species beloning to the family Channide. Koshi Barrage, a part of Koshi River, lying in the district Sunsari and Saptari; of Nepal was choosen as a site, for the study. Fishes caught alive or in fresh condition, were collected, fixed with 40% formalin, photographed and preserved in 10% formalin, labeling them, giving serial numbers, the name of exact locality from where they have been collected; date of the collection and their local name on each jar and preserved. The fishes were identified using a website www.fishbase.com and other available resources. Five species of fishes belonging to the family Channidae were identified and taxonomic study was carried out at an international level. Further scientific reaearch is only possible after the correct identification. So, it is supposed to be the most important study; as fishes are the best alternative sources of protein and may carry many other values in the field of medicines against different challenging diseases. This is possible only when the fishes are identified correctly. Out of 5 species, 3 of them; Channa gachua, Channa marulius and Channa striatus; is investigated to be a new report in the context of Nepal, as it is not mentioned in the fishbase.