Vietnam is known as the high diversity of genus Lithocarpus Blume-Fagaceae. In the flora of Vietnam, Lithocarpus comprises 10 subgenera, 115 species and 2 variations which is accounting for nearly 40 percent of the total of Lithocarpus species in the world. In this article, the authors identified the classification position of Lithocarpus Blume belonging to Castanoidae, Fagaceae, Fagales, Dicotyledones. Angiospermae. the authors explained the generalized major morphological characteristics such as: Habit, terminal buds, leaves and stipules, flowers and inflorescence, fruits, cupule and acom. Based on the morphological characteristics of reproduction organs, the authors made the dichotomous key of 10 subgenera of Lithocarpus Blume in Vietnam. the authors also counted the nomenclature and described the detailed morphological characteristics of 10 subgenera belonging to Lithocarpus in Vietnam.