Objective To investigate the effects on thymic factor D(TFD) anti-liver fibrotic in vivo Methods Rat liver fibrosis model was developed by means of induction with carbon tetrachloride(CCl 4).Rats in TFD prevention group were given TFD at the time of first injection of CCl 4.Rats in TFD treatment group were given TFD 30 days after first injection of CCl 4.At the end of the experiment,liver function and pathological examination were analysed.The following indexes of hepatofibrosis including level of serum procollagen type-Ⅲ(PC-Ⅱ),hyaluronic acid (HA) and laminin (LN) were examined.Levels of glutathione (GSH),Superoxide dismutase (SOD) and malondialdehyde (MDA) in hepatic tissue were measured as well.Results CCl 4-induced liver fibrosis was ameliolated by TFD significantly.The serum PC-Ⅲ,HA,LN and hepatic tissue MDA were significantly reduced.The activities of GSH and SOD were increased and liver function were improved.The histological examination also demonstrated its anti-fibrotic effect.Conclusion TFD has anti-fibrotic effect on liver in vivo,and may have potential value for clinical use.