Abstract: Data from two-vessel investigation in Yellow River delta have been used to examine the surface bouyant plumes during the ebb period,together with the remote sensing image. Concentration of suspended matters, water temperature and salinity change dramatically in surface water within 5 km beyond Yellow River delta; concentration descreases from 519 to 20~30 mg/L and temperature drops by 4℃, while water salinity increases from 1 to 33. These variations correspond with each other, showing the mixture of river outflow with seawater. The remote sensing image indicates complicated pattern of suspended matter scattering, which can correlate with the field data. Mean grain size of suspended matters in surface water range from 6.64 to 5.26 Φ,coarsing towards the sea.Granulometric parameters of surface water at the Yellow River mouth are different from those of the Yangtse River estuary.