China marginal seas(CMS,including the Bohai Sea,the Yellow Sea,the East China Sea), are a significant sink for both terrestrial organic matter(TOM) and marine OM (MOM).Both the sources and distributions of OM in China marginal seas have been affected by rapid climate changes and anthropogenic activities over the last 60 years.The total organic carbon(TOC) proxies and biomarker results of surface sediments indicated that higher percentage of TOM (% TOM) occurred near coastal regions and especially near river mouths such as the Yellow River Estuary,the old Huanghe Estuary and the Changjiang River Estuary.Higher percentage of MOM values were found in shelf sea basins,controlled by the marine primary production and depositional settings.Quantitative estimates based on both TOC and biomarker proxies with binary or ternary models revealed that total a sequestration of 13Mt/a TOC buried in CMS(~10% of global continental margin sediments) and burial TOM accounted for ~7% that of global continental margin sediments.If we assumed non-modern OM (including pre-aged and fossil OM) was mainly terrigenous,then the percentage of non-modern OM in CMS was~46%, comparable to the% TOM (44%) of global continental margin sediments.The preliminary carbon budget in the CMS indicated that it plays an important role in the global marine carbon cycle.This paper sunmaries the sources of sedimentary organic matter in china maginal sea surface sedments and implications of carbon sink using published data.