This study was designed to investigate the protective effects of Acanthus ilicifolius alkaloid A [4-hydroxy-2-benzoxazolone (HBOA)] and its acetylated derivatives including 4-acetoxy-2-benzoxazolone (TC-2) and 3-acetyl-4-acetoxy-2-benzoxazolone (TC-3) on carbon tetrachloride (CCl4 )-induced liver fibrosis in rats. Sprague-Dawley rats were given CCl4 twice per week for 8 weeks to induce liver fibrosis. Then, they were treated with HBOA, TC-2, and TC-3 daily for 4 weeks, respectively. The serum indicators including total protein (TP), albumin (Alb), globulin, hyaluronic acid (HA), and laminin (LN) were measured by commercial kits. The messenger ribonucleic acid expression of adiponectin, peroxisome proliferator-activated receptor-γ (PPAR-γ), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), transforming growth factor-β1 (TGF-β1 ) and Toll-like receptor 4 (TLR4 ) was determined by reverse-transcriptase -PCR. The proteins of adiponectin, TGF-β1 , α-smooth muscle actin (α-SMA), and TLR4 were also detected by the immunohistochemical assay. The results showed that HBOA, TC-2, and TC-3 significantly attenuated the fibrotic degree induced by CCl4 as evidenced by higher levels of TP, Alb, adiponectin, and PPAR-γ, which in turn decreased the proliferation of hepatic stellate cells. Moreover, those drugs markedly decreased the levels of HA, LN, TNF-α, IL-6, TGF-β1 , α-SMA, and TLR4 . Our study indicates that HBOA, TC-2, and TC-3 have beneficial effects against liver fibrosis, and the mechanisms may be related to the inhibition of inflammatory response.