Objective：To construct recombinant expression vector of human augmenter of liver regeneration (ALR) and study its protective effect on liver function. Methods: ALR cDNA was synthesized and inserted into expression vector pET28a+. The recombinant plasmid was tranformed into BL21 and the expression of ALR was induced by isopropyl-β-D-thiogalactoside(IPTG). MTT method was used for cell proliferation assay; the protective effect of recombinant product on liver function was observed in CCl4-induced acute toxic mouse model. Results: Recombinant expression plasmid of ALR was confirmed correct by restriction enzyme digestion and sequencing. The purified expression product had strong stimulatory effect on hepatocyte proliferation. Low and medium dosages of expression product decreased aminotransferase level in acute chemical injury mouse model.Conclusion: The recombinant expression vector of ALR has been correctly constructed and the expressed rALR can simulate hepatocyte regeneration.