Using in-situ observational data on the Chukchi shelf and at Bering Strait in winter 2020, the hydrography and water masses are analyzed. The vertically structures of the temperature and salinity were fairly uniform at most of the stations, implying the strong vertical convection during observation. The timeseries of watermasses showed that there were two regions in which the newly-ventilated winter water near freezing point were dominant, the north-central region with relatively salty water, and the strait region with low salinity values shown up. Local and broad ice concentrations, and wind conditions are analyzed to investigate the mechanism of the different salinity in the two winter water regions.