Objective: To study the variation of plasma inflammatory cytokine IL-6 and antiinflammatory cy-tokine IL-10 in patients with acute and old myocardial infarction, patients with acute myocardial infarction before and after thrombolytic therapy. Methods: 24 patients with acute myocardial infarction (10 patients subjected to thrombolytic therapy) and 20 patients with old myocardial infarction were studied. Plasma levels of IL-6 ang IL-10 were detected by ELISA. Results: In this study, significantly increased level of IL-6 and IL-10 were observed in patients with acute and old myocardial infarction. Plasma levels of LL-6 and IL-10 were significantly higher in acute myocardial infarction group compared with old myocardial infarction group. IL-10 levels were obviously decreased and EL-6 level were slightly increased in patients with acute myocardial infarction after thrombolytic therapy. From the statistic analysis, we have demonstrated that there were significant positive correlation between IL-10 and crea-tine kinade(CK), IL-10 and creatine kinade-MB(CK-MB), respectively. Conclusion: Our studies demonstrated increased plasma levels of DL-1 and EL-10 in patients with acute myocardial infarction. They could probably regulate each other in myocardial ischemia and reperfusion.