ABSTRACT: A first report on the Neogene diatoms from the deep Hole Central-1 drilled on the Chukchi shelf of the Bering Sea is presented. The studied interval (609.5-623.5 meters below the sea floor) contains more than 70 diatom taxa incore samples collected from tuffaceous-diatomite sequence. The diatom flora is dominated by marine neritic-planktic and sublittoral taxa which implies deposition in productive shallow water environments. The occurrence of biostratigraphically- significant marine taxa Pyxidicula zabelinae, Cosmiodiscus insignis, and Ikebea tenuis indicate a Late Miocene age with a range of about 7.9 to 5.5 Ma.