The chemical investigation of Penthorum chinense resulted in the isolation of two new phenylpropanoids (1 and 2) along with three known compounds (3-5). The structures of the compounds 1 and 2 were determined by interpretation of the spectroscopic data, including IR, HR-ESI-MS, H-1 NMR, C-13 NMR, DEPT, COSY, HMBC and HMQC. Moreover, all the compounds were evaluated for their hepatoprotective activity in H2O2 -induced cytotoxicity in HL-7702 cells, and compounds 2-4 (2.5 mu g/mL) showed a moderate hepatoprotective activity against H2O2-induced cell damage.