A new species of the genus Dendrocalamus Nees (Poaceae: Bambusoideae), D. concaviapiculus N.H.Xia et V.T.Nguyen, sp. nov., is described and illustrated from Yen Bai and Phu Tho provinces, Vietnam. It differs from other related Dendrocalamus species by its 5-veined palea between keels and without any vein, its apex and ligule of culm sheath concave, its culm sheath blade short, and its flexuose basal culm internodes.