Thispaperfirstdevelopstheapproachestodeterminethegeopotentialofthelocalmeansealevel,andtheninvestigatestheoffsetofthe1985verticaldatumsurfacedefinedbythemeansealevelofYellowSeaattheDagangTideGaugeinQingdaocityusingthedevelopedapproachesandGPS/levelingdata.Itshowsthatthegeopotentialofthelocalmeansealevelatthetidegaugeisequalto62636853.5±0.2m2*s-2andthatthe1985verticaldatumsurfaceis24.6±5.4cmabovethegeoidrealizedbythegeopotentialW0=62636856.0±0.5m2*s-2.
