Objective:To investigate the regulation effects of bone morphogenetic protein-4 (BMP-4) on the proliferation and differentiation of rat hepatic oval cells (HOC).Methods:Applying recombinant Noggin or adenovirus-BMP4-shRNA as the function blocker of BMP-4, rat HOC were treated with recombinant BMP-4 and adenovirus-BMP4 for different time points, We also operates control groups with Empty adenovirus or nothing. The proliferation of HOC were tested by methyl thiazolyl tetrazolium (MTT) colorimetric assay. The ultrastructural characters of differentiated HOC regulated by BMP-4 were observed under a transmission electron microscopy. The method of RT-PCR was employed to examine mRNA expression of specific molecular markers for different cellular phenotypes potentially differentiated from the progenitor cells of HOC. We apply PAS staining and ICG uptake staining to test whether the induced cells possess liver cell functions of synthesis glycogen and Indocyanine green metabolism.Results:At different experimental time points, the absorbance values in BMP-4 treatment groups were respectively higher than that in the groups of Noggin and blank treatment (p<0.01, respectively). The HOC cells treated with BMP-4 exhibited typical ultrastructural characters of well-differentiated epithelial cells. The hepatocyte mRNA markers were significantly promoted in differentiated HOC in BMP-4 treatment group than that in the control groups. The cells induced by BMP-4 possess nomal hepatocellular functions of synthesis glycogen and Indocyanine green metabolism.Conclusion:BMP-4 can promote the proliferation and a directional differentiation towards hepatocytes of hepatic epithelial stem-like HOC and the differentiated cells derived from HOC with BMP4-treatment have nomal hepatocellular functions of synthesis glycogen and Indocyanine green metabolism.