The aim of this study was to investigate that Injinoryung-san-Ga-Samchilgun(IJORS) has an inhibitory effect on the development of liver fibrosis in rats. The influence of IJORS on liver stellate cell viability in rat was measured by the MTT assay, and proliferation was measured by the BrdU assay. The mRNA expression of procollagen type $1{alpha}2$, ${alpha}-SMA$, TIMP1, and TIMP2 all of which are associated with liver fibrosis, were analyzed by RT-PCR. The inhibitory effect of IJORS on procollagen production in hepatic stellate cell was examined using by enzyme immuno assay(procollagen Type 1 C-Peptide EIA). And after IJORS was orally administered to experimental rats with thioacetamide(TAA)-induced liver fibrosis for 4 weeks, the body weight, liver function test, complete blood and the change of portal pressure were measured. IJORS prevented hepatic stellate cell viability and proliferation in a dose-dependent manner. IJORS reduced the mRNA expression of procollagen type $1{alpha}2$, ${alpha}-SMA$ and TIMP1 and the production of procollagen protein. IJORS inhibited the increase of AST, ALT, WBC and portal pressure in rats administered by TAA. IJORS is considered to prevent liver fibrosis by inhibiting the activation of stellate cell and production of procollagen and prevent the progress of liver fibrosis by inhibiting the inflammation of liver tissue complicated in many liver disease.