OBJECTIVE:To study the antitumor activity and antioxidative action of glycosaminoglycan from scallop skirt(SS-GAG).METHODS:The effects of different concentration of SS-GAG on the proliferation of four tumor cell lines(HeLa,LOVO,A549,and U251)which had been cultured in vitro were observed by MTT.The effect of SS-GAG on mice within 30 d after innoculation of sarcoma 180 was observed.Multi-kind of biochemistry methods including xanthine oxidase method and thiobarbituric acid colorimetric method were used to study the effect of SS-GAG on total antioxidation activity,activity of SOD,and level of MDA in tumor-bearing mice,which were compared with those in control group.RESULTS:As compared with control group,SS-GAG significantly inhibited the growth of HeLa and U251 cell lines,inhibited the growth of LOVO and A549 cell lines to some degree,significantly prolonged the survival time of the mice with S180 ascites tumor,enhanced the total antioxidant activity and the SOD activity and decreased MDA content in serum(P