Objective To observe the change of platelet activity marker in hypertensive patients complicated with ischemic cardiovascular and cerebrovascular disease ,and assess it s value in the happening of thrombotic disease. Method The platelet activity marker (CD62p,CD63) were measured by flow cytometry in 40 hypertensive patients complicated with ischemic cardiovascular and cerebrovascular disease (group C ),46 hypertensive patients not complicated with ischemic cardiovascular and cerebrovascular disease (group B),and 30 cases of healthy control (group A). Comparison between three groups were made. The serum fibrinogen were measured at the same time. Result serum level of CD62p, and CD63 in group B,C are higher than group A.(P