In this study, the anticoagulant compounds in Korean red ginseng (KRG) were investigated. KRG powder was extracted using hot methanol, and the methanol extract was fractionated into n-hexane, ethylacetate, n-butanol, and aqueous fractions by solvent partitioning. The remains from the methanol extraction were further extracted with water and then dialyzed to obtain low and high molecular weight fractions. The anticoagulant activities of the seven fractions were evaluated in terms of thrombin time, prothrombin time, and activated partial thromboplastin time. Among these fractions, the ethylacetate fraction showed the most potent anticoagulant activity. The active components in the ethylacetate fraction were identified as the phenolic compounds vanillic, caffeic, ferulic, and p-coumaric acid via TLC and HPLC. These findings suggest that the anticoagulant activities of phenolic compounds contribute to the cardiovascular effects of KRG.