The study on coral reef fish species composition in the coastal areas of North Hai Van - Son Cha, Thua Thien Hue province was carried out in the period from January, 2020 to October, 2022 at 4 sites, namely Bai Ca, Bai Chuoi, Sung Rau Cau, Son Cha island to update scientific data to contribute to establishing the marine reserve. Fish were collected using fish nets, fish traps, scoops and spears every two months. 142 coral reef fish species belonging to 94 genus, 48 families and 23 orders were found. There were 5 orders with large number of species such as Perciformes (36 species), Ovalentaria (20 species), Kurtiformes (14 species), Labriformes (13 species) and Tetraodontiformes (8 species). Other orders had from 1 to 5 species. Fish species composition abundance was different between the study sites, of which the highest diversity was found at Son Cha island, with 71 species belonging to 48 genus, 28 families and 16 orders while the poorest composition was recorded at Bai Ca, with 51 species belonging to 35 genus, 24 families and 13 orders.