The flora of Na Hau Natural Reserve in Yen Bai province is diverse in species composition , usable value, life forms and especially conservation values. The results of research shown that there are 657 species belong to 440 genera and 154 families has been recorded. This flore with some dominant families such as Poaceae, Euphorbiaceae, Asteraceae, Moraceae, Rubiaceae, Orchidaceae, Fabaceae, Lauraceae... The existence of a variety life-forms reflects the typically tropical characteristics of the flore at the Na Hau Natural Reservation Area