Abstract: The contents and compositions of amino sugars (ASs) were investigated in the surface sediments of the Bohai Sea. Combined with analysis of total organic carbon (TOC), total nitrogen (TN), stable carbon isotope (δ¹³C) and grain size, the sources of sedimentary organic matters (SOM) and bacterial contributions were studied. The concentrations of ASs ranged from 0.22 to 1.89 μmol/g, with an average value of (1.01 ± 0.52) μmol/g in the surface sediments of the Bohai Sea. According to the two end-members mixing model, the fractions of terrigenous organic matter (f_t) ranged from 28.1% to 42.8% in the surface sediments, which gradually decreased from the Yellow River Estuary to the sea. The deposition of “low organic carbon” sediments of the Yellow River may be responsible for low TOC, TN and ASs contents in the surface sediments of the Yellow River mouth and the Bohai Strait. However, the relatively high contents of TOC, TN and ASs may be related to the effects of clay minerals and primary production on SOM in the sites where less affected by the Yellow River. The average contributions of ASs to TOC and TN (AS-C% and AS-N%) were (1.5 ± 0.7)% and (1.9 ± 0.9)%, respectively. The ratios of glucosamine to galactosamine (GlcN/GalN) below 3, indicating that bacterial organic matter may be the main source of ASs in the surface sediments of the Bohai Sea. The mean contributions of bacterial organic matter to TOC and TN (Bacteria-C% and Bacteria-N%) in the surface sediments of the Bohai Sea were (10.7 ± 8.3)% and (12.6 ± 9.6)%, respectively.