Abstract: OBJECTIVE To investigate schizandrin lignan relieving angiotensin II(Ang II) induced oxidative stress damage of human umbilical vein endothelial cells(HUVEC) and explore its internal mechanism. METHODS HUVEC were incubated with a certain concentration gradient of schisandrin B(Sch B) and schisandrin C(Sch C) for 24 h. Annexin V-FITC/PI double staining method was used to detect changes in cell apoptosis. DCFH-DA and DHE probes was used to detect the expression of intracellular reactive oxygen species. RT-qPCR was used to detect the levels of Bax and Bcl-2 mRNA, the antioxidant protein nuclear factor E2 related factor(Nrf-2), heme oxygenase-1(HO-1) and quinone oxidoreductase(NQO-1) mRNA expression. Western blotting was used to detect the expression of Bax, Bcl-2, Nrf-2 and Kelch-like epichlorohydrinrelated protein-1(Keap-1). Used specific siRNA to construct HUVEC with low expression of Nrf-2, and explore whether Schisandra lignans target Nrf-2 to alleviate Ang II-induced oxidative stress damage. RESULTS Using Sch B(50 μmol·L^-1) and Sch C(26 μmol·L^-1) in the HUVEC injury model induced by Ang II, it was found that Sch B and Sch C could inhibit cell apoptosis(P < 0.01 or P < 0.001) and ROS level(P < 0.05) by regulating the antioxidant axis Nrf-2/Keap-1, promoting the expression of HO-1(P < 0.05), NQO-1(P < 0.05) and other antioxidant enzymes, and effectively relieved H₂O₂-induced oxidation stress injury. In HUVEC that specifically silenced Nrf-2, it was found that Sch B, Sch C can target Nrf-2 to activate the expression of downstream antioxidant enzymes(NQO-1, HO-1) and relieve the oxidative stress damage induced by Ang Ⅱ. CONCLUSION Sch B and Sch C can relieve Ang II-induced oxidative stress damage in HUVEC by regulating the Nrf-2/Keap-1 antioxidant pathway.