Aim To investigate the relationship between platelet CD62P and CD63 expression and acute cevebral infarction(ACI). Methods The expression of CD62P,CD63 was detected by flow cytometry in 61 patients with acute cevebral infarction(ACI),and 59 healthy control subjects. Results CD62P,CD63 in acute cevebral infarition were 6.26%±1.68% vs 2.32%±1.14%,6.14%±1.89% vs 2.88%±1.15% respectively,and the result has statistical significance compa with those of the control group(P><0.01). Conclusion The formation of thrombus in actute cerebral infaration patients is highly related to the platelets activation,which can be a diagnostic indicator of cevebral infarction disease.