Abstract: The influence of four kinds of polysaccharide sulfate〔heparin ( Hep) ,lowmolecular weight heparin( LMWH),proglyene glucol mannate sulfate(MS₈₇₁) ,chondroitin Asulfate(CAS)〕on HUVEC injured by polycations and oxygen free radicals was investigated. Thedegree of injury was determined by checking the release of LDH to medium and 3H-TdR incorpora-tion. The four kinds of polysaccharide sulfate were shown to protect cells from injury caused by polyly-sine concentration-dependently. The study also showed that the effects of Hep and CAS were strongerthan those of LMWH and MS₈₇₁ at the same dase level. In view of the level of LDH, the four kinds ofpolysaccharide sulfate can protect cells from oxygen free radical injury.The effects of Hep and CASwere more active than those of LMWH.