AIM: To investigate the effects of eukaryotic expression of plasmid on augmentation of liver regeneration (ALR) in rat hepatic fibrosis and to explore their mechanisms. METHODS: Ten rats were randomly selected from 50Wistar rats as normal control group. The rest were administered intraperitoneally with porcine serum twice weekly. After 8 wk, they were randomly divided into:model control group, colchicine group (Col), first ALR group (ALR1), second ALR group (ALR2). Then colchicine ALR recombinant plasmid were used to treat them respectively. At the end of the 4th wk, rats were killed.Serum indicators were detected and histopathological changes were graded. Expression of type Ⅰ, Ⅲ, collagen and TIMP-1 were detected by immunohisto-chemistry and expression of TIMP-1 mRNA was detected by semiquantified RT-PCR.RESULTS: The histologic examination showed that the degree of the rat hepatic fibrosis in two ALR groups was lower than those in model control group. Compared with model group, ALR significantly reduced the serum levels of ALT,AST, HA, LN, PCⅢ and Ⅳ (P＜0.05). Immunohistochemical staining showed that expression of type Ⅰ, Ⅲ, collagen and TIMP-1 in two ALR groups was ameliorated dramatically compared with model group (Ⅰ collagen: 6.94±1.42, 5.80±1.66and 10.83±3.58 in ALR1, ALR2 and model groups, respectively;Ⅲ collagen: 7.18±1.95, 4.50±1.67 and 10.25±2.61,respectively; TIMP-1: 0.39±0.05, 0.20±0.06 and 0.53±0.12,respectively, P＜0.05 or P＜0.01). The expression level of TIMP-1 mRNA in the liver tissues was markedly decreased in two ALR groups compared with model group (TIMP-1mRNA/β-actin: 0.89±0.08, 0.65±0.11 and 1.36±0.11 in ALR1, ALR2 and model groups respectively, P＜0.01).CONCLUSION: ALR recombinant plasmid has beneficial effects on rat hepatic fibrosis by enhancing regeneration of injured liver cells and inhibiting TIMP-1 expressions.