The study was conducted through seven surveys from October 2021 to July 2023, in five estuaries of Thanh Hoa province, including Cua Hoi, Lach Truong, Lach Ghep and Lach Bang. As a result, 5 species were identified belonging to 3 genera in Terapotidae; one species (Pelates quadrilineatus) has been added compared to previous studies of Duong Quang Ngoc (2007), Nguyen Xuan Huan et al. (2014). Compared to number of species in Vietnam, the species composition of the Terapotidae in the study area is quite diverse, accounting for 63% of the currently known species in Vietnam.