By using smooth muscle cell (SMC) culture in vitro and H3-TdR incorporation technique, we tested the effect of Emodin on SMC proliferation in three groups: (1) Normal rabbit iliac artery, (2) atherosclerotic rabbit iliac artery, (3) atherosclerotic rabbit iliac artery after PTA. These data indicated: Emodin has antiproliferative effect on SMC, which is dose dependent; it blocks the transition of SMC cycle from G0 to S. In PTA group it exerts a more significant proliferative effect than in the normal one. This is a the first report of Emodin's effect on SMC proliferation, it implies that the drug may be used clinically to prevent restenosis after PTCA.