To study the effect of matrine on proliferation of mouse skin fibroblasts induced by platelet-derived growth factor-BB (PDGF-BB). Methods: Mouse skin fibroblasts were obtained from newb ⅠCR mice and propagated in vitro. Proliferation of cell was analyzed by mitochondrial reduction of tetrazolium salt MTT and actual cell count. Results: Matrine (50 to 500 μg/ml) caused dose-dependent reduction of serum-stimulated cell growth. Growth inhibition was totally reversed after removal of the drug. Matrine also inhibited PDGF-BB induced cell growth dose-dependently. Conclusion: Matrine exhibits potent anti-proliferation effect on mouse skin fibroblast. This effect appears to be mediated by decrease of PDGF-induced growth. These results suggest that matrine might have preventive and therapeutic implication in skin fibrosis.