Here, we demonstrated that downregulation of PDGFR-β by RNA interference (RNAi) could also result in the inhibition of ERK phosphorylation; thus, the blockage of the MAPK signal transduction pathway and the suppression of HSCs proliferation in vitro, the liver injury and hepatic fibrosis induced by DMN and BDL could also be relieved by PDGFR-β shRNA treatment. The gene discussed is PDGFRB; the disease is Hepatic fibrosis.