Polysaccharide from Sanguisorba officinalis was separated and fractionated using DEAE-Sephadex ion-exchange chromatography and Sephacry HR-200 gel filtration chromatography. One of the fraction(Fr. II) was sulfated and its anticoagulant activity was tested in vitro. Sulfation could increase the clotting time 50 times compared to unsulfated one. Fr. II was hydrolyzed and its composition was analyzed by conjugation with 7-amino-1, 3-naphthalene disulfonic acid using HPLC and electrophoresis. Arabinose and galactose were mainly composed at the ratio of 4 : 1. In addition, xylose and rhamnose were also found.