Aim To investigate the possible signal transduction pathway by which IL 10 inhibits the proliferation of vascular smooth muscle cells (VSMC) induced by angiotensin Ⅱ (AngⅡ). Methods 3 H TdR and 32 P ATP incorporation were used to detect the proliferation of VSMC and the activity of mitogen activity proteinkinase(MAPK) and protein kinase C (PKC), respectively. Western blot and immunoprecipitation were applied to assay the expression and activity of focal adhesion kinase (FAK), respectively. Results IL 10 inhibited VSMC proliferation induced by AngⅡ, and down regulated AngⅡ induced activition of MAPK, PKC and FAK(P<0.05 orP<0.01). Conclusions The results suggest that the inhibiting effect of IL 10 on AngⅡ stimulated VSMC proliferation may be mediated by down regulating MAPK, PKC and FAK activity stimulated by AngⅡ.