Objective To investigate the therapeutic effects and mechanisms of curcumin derivatives C66 treatment on hepatic fibrosis .Methods Thirty three C57BL/6J mice were randomly divided into 3 groups:normal control group ,model control group and curcumin derivatives C66 treatment group .Nine mice in normal control group were fed with water and food .Hepatic fibrosis model was induced in 24 mice by intraperitoneal injection of 40% carbon tetrachloride at a dose of 4 mL/kg for the first time ,followed by 2 mL/kg twice a week for 6 weeks . At week 6 ,6 mice were randomly selected to perform pathological examination to evaluate whether the hepatic fibrosis were successfully induced .Mice with hepatic fibrosis were randomized into model control group and curcumin derivatives C66 treatment group with 9 mice in each group .From week 6 on ,mice in the treatment group were lavaged with curcumin derivatives C66 at a dosage of 10 mg ·/(kg · d) .The rest mice were administered with equivalent dosage of 0 .5% carboxymethylcellulose sodium .Serum alanine aminotransferase (ALT) ,aspartate aminotransferase (AST ) and liver hydroxyproline ( Hyp ) contents were detected , and the semi‐quantitative analysis of liver fibrosis was performed by pathological examination in hepatic tissue by hematoxylin and eosin (HE) and Masson staining .The expressions of collagen Ⅰ ,α‐smooth muscle actin (α‐SMA) mRNA and collagen Ⅰ ,α‐SMA ,nuclear factor‐kappa B p65 (NF‐κB p65) ,inhibitor kappa B alpha (IκBα) protein in each group were detected by quantitative real‐time polymerase chain reaction (RT‐PCR) and Western blot .Data were analyzed with one‐way ANOVA analysis .Results The serum levels of ALT and AST in model control group ,C66 treatment group and normal control group were (202 .71 ± 19 .66 ) U/L , (233 .42 ± 23 .97 ) U/L ;(102 .00 ± 11 .04 ) U/L , (120 .87 ± 13 .83 ) U/L ;(36 .66 ± 6 .37) U/L and (43 .33 ± 8 .08)U/L ,respectively .The differences between model and normal control group were both significant (t=23 .96 and 22 .39 ,respectively ;both P<0 .05) .The C66 treatment group showed significantly lower levels of serum ALT and AST in contrast with model control group (t =11 .56 and 10 .52 ,respectively ;both P<0 .05) .Compared to the model control group ,hepatic Hyp contents in normal control group and C66 treatment group were significantly different (t= 17 .50 , P< 0 .05;t=11 .45 ,P<0 .05) .Collagen Ⅰand α‐SMA mRNA expressions in C66 treatment group were remarkably lower in contrast with that in model control group (t= 7 .23 and 7 .95 ,respectively ;both P< 0 .05) . Protein levels of Collagen Ⅰ ,α‐SMA and NF‐κB p65 decreased in C66 treatment group ,while IκBαincreased significantly (all P<0 .05) .Conclusion The application of C66 can contribute to the regression of liver fibrosis and the mechanism may rely on the regulation of NF‐κB expression .