Chinese Arctic and Antarctic Administration (CAA) organized the 1st to 4th Chinese National Arctic Expeditions in 1999, 2003, 2008 and 2010, respectively.Some samples of box-cores, multi-cores and gravity-cores were collected in the western Arctic Ocean during these cruises for sedimentologic and paleoceanographic researches.A total of more than 140 samples from the surface sediments have been investigated on spatial distribution patterns in biogenic (CaCO3 and foraminiferal abundance, TOC, opal, planktonic oxygen and carbon isotopes and benthic assemblage, etc) and non-biogenic sediments (IRD and grain size, clay mineral, etc) and their relationship with recent environmental factors.These studies provide an important base for reconstruction of paleoceanography and paleoclimate in this area.Sediments often gravity cores collected in the western Arctic Ocean during these cruises have been studied on stratigraphy, sedimentology, micropaleontology, geochemistry, mineralogy and petrology, etc.Late Quaternary paleoceanographic changes in the Western Arctic Ocean (Chukchi Abyssal Plain, Chukchi Plateau and Alpha Ridges) are revealed by quantitative investigations on foraminiferal abundance, IRD and its mineralogical and petrological compositions, oxygen and carbon isotopes of N.pachyderma (sin.), biogenic and non-biogenic components.