OBJECTIVE:To investigate the inhibitory effects mechanism of scallop skirt glycosaminoglycan(SS-GAG)on inju-ry in human umbilical vein endothelium cells (HUVEC). METHODS:In the test,there was a negative control group,a model group and the groups of SS-GAG at high,middle and low concentrations(mass concentrations of 200,100 and 50 mg/L respective-ly). The cells in latter 3 groups were cultured in SS-GAG at different mass concentrations for 12 h,and then in 50 μmol/L oxidized low-density lipoprotein(OX-LDL)for 24 h. MTT method was used to detect cell viability and the activity of lactic dehydrogenase (LDH),the flow cytometer to determine the level of reactive oxygen species (ROS),real-time fluorescence quantitative poly-merase chain reaction (RT-PCR) to detect mRNA expression of lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1), and Western blot to detect NOX4 protein expression. RESULTS:Compared to the cells in the negative control group,those in the model group demonstrated lower viability,higher activity of LDH,higher level of ROS,and stronger expressions of LOX-1 mRNA and NOX4 protein. There was statistical significance (P<0.01). Compared to the cells in the model group,those in the groups of SS-GAG at high,middle and low concentrations showed higher viability,lower activity of LDH,lower level of ROS and weaker expressions of LOX-1 mRNA and NOX4 protein. There was statistical significance (P<0.01). CONCLUSIONS:SS-GAG can protect HUVEC to some degree by a mechanism which may be related to inhibiting ROS production via LOX-1/NOX4 pathway and relieving oxidative stress injury.