Abstract: OBJECTIVE To design and synthesis a series of N-acetylcysteine derivatives, as well as evaluate the protective effects of the target compounds on H₂O₂-induced oxidative injury on LO2 cells. METHODS A series of novel N-acetylcysteine derivatives were synthesized by acyl chloride esterification method from L-cysteine and N-acetylcysteine. The in vitro oxidative injury model was established by inducing H₂O₂ into the LO2 cells. The effects of different concentrations of H₂O₂ on the LO2 cell survival rates were detected by CCK-8 kit, and the contents of MDA and the activities of SOD were measured in the cell culture supernate. RESULTS Six novel N-acetylcysteine derivatives were synthesized and the structures were confirmed by ¹H-NMR, ¹³C-NMR and ESI-MS. The target compounds could alleviate H₂O₂-induced oxidative injury on LO2 cells, reduce the concentrations of MDA and increase the activities of SOD(P<0.01 or P<0.05). CONCLUSION A series of novel N-acetylcysteine derivatives are designed and synthesized, which display protective effects on hepatocytes injury induced by H₂O₂.