Abstract: The diatom from Great Xing'an Mountains were studied following the new classical system of the international diatom research. During the study, many new record genera and species were observed. In this paper, 10 taxa belong to 10 genera were reported and the detail morphological characters were given. Among them, 3 genera were newly recorded genera in China, they are: Boreozonacola Lange-Bertalot, Kulikovskiy Witkowski, Chamaepinnularia Lange-Bertalot Krammer and Microcostatus Johansen Sray. Another 7 genera were reported in China before, but the morphological characters were not given by the former studies, in this paper, morphological descriptions of these 7 genera were given to provide basic informations for other studies. Nine newly recorded species and 1 variety were observed, they are: Boreozonacola hustedtii Lange-Bertalot, Kulikovskiy Witkowski, Chamaepinnularia hassiaca (Krasske) Cantonati Lange-Bertalot, Microcostatus maceria (Schimanski) Lange-Bertalot, Cavinula heterostauron (Germain) Van de Vijver, Diadesmis ingeaeformis Hamilton Antoniades, Geissleria paludosa (Hustedt) Lange-Bertalot Metzeltin, Hippodonta neglecta Lange-Bertalot, Metzeltin Witkowski, Luticola charlatii (Peragallo) Metzeltin, Lange-Bertalot, Mayamaea atomus var. permitis (Hustedt) Lange-Bertalot, Neidiopsis levanderi (Hustedt) Lange-Bertalot Metzeltin.