Abstract: Sediment samples from the previous China Arctic Expeditions in the north continental slope and deep basin of Bering Sea were used for sedimentology studies. Abnormal sedimentary types and their characteristics were summarized, and the possible causes were preliminarily discussed. At least three turbidite layers appear in core BR02, which distributing mainly from the last deglacial to Mid-Holocene. More than two volcano clastic sedimentary layers were affirmed in Core B5-4, which formed at ca. 1.3 kaBP and 13.2 kaBP respectively. Diatom assemblage of surface sediment of Core B5-7 is dominated by Neogene fossil diatoms of Kisseleviella carina Sheshukova-Poretzkaya and Kisseleviella ezoensis Akib, which is distinctively different from that of other adjacent surface sediments. We presume it could be the result of reworking and its initial depositional age could be about the early Miocene. The numerous submarine canyons incising the continental margin of the Bering Sea may exert great impact on sedimentation processes, which could be the main reason of kinds of abnormal sedimentation processes around this sea area. Moreover, the special locality of Bering Sea along the margin between the Eurasian plate and the North American plate is also decisive for it frequently suffering from earthquakes and volcanic activities, which in turn promote submarine abnormal sedimentation processes to occur more frequently.

Key words: Bering Sea, abnormal sedimentation process, turbidity, tephra, reworked sediment