Abstract: OBJECTIVE To explore the effect of tanshinone on ischemia reperfusion injury of rabbits after acute myocardial infarction, and to supply the experimental proof for the clinic. METHODS Divide 40 male rabbits into 4 groups, 10 per group: glucose reperfusion group, tanshinone reperfusion group, tanshinone pre-blocking treatment group and sham-operation group. Reperfusion injury model was established and the drug was administrated intravenously. Blood was collected to test the CK, CK-MB, Tn-Ⅰ at the time of 5 min pre-blocking, 1 h post-blocking and 2 h post reperfusion. 1% Triphenyltetrazolium chloride was used to produce myocardial incision. AutoCAD 2002 software was applied to calculate the area of myocardial infarction. RESULTS ①Tanshinone reperfusion group and glucose reperfusion group had significant differences in CK, CK-MB, Tn-Ⅰ after 2 h reperfusion(P<0.05). Tanshinone pre-blocking treatment group and glucose reperfusion group had significant differences in CK, CK-MB, Tn-Ⅰ after 2 h reperfusion(P<0.05). Tanshinone reperfusion group and tanshinone pre-blocking treatment group had no significant differences in CK, CK-MB after 2 h reperfusion(P>0.05), and had significant differences in Tn-Ⅰ after 2 h reperfusion(P<0.05). ②The area of myocardial infarction between tanshinone reperfusion group and glucose reperfusion group, tanshinone pre-blocking treatment group and glucose reperfusion group had significant differences(P<0.05). The area of myocardial infarction between tanshinone reperfusion group and tanshinone pre-blocking treatment group had no significant differences(P>0.05). CONCLUSION Tanshinone can lower CK, CK-MB, Tn-Ⅰ of rabbits with acute myocardial infarction, and can decrease the area of myocardial infarction.