Objective To explore the inhibitory effect of aprotinin on general inflammatory reaction in cardiopulmonary bypass(CPB),Methods 16 patients with cardiac valves substitution were equal divided at random two groups;control group and aprotinin group.Before the CPB operation,40min during CPB period,30min,4h after CPB termination,the integrin CD 11b expression of neutrophilic granulocytes in heparinization arterial blood was determined by using flow cytometer.Results 30min,4h after CPB operation termination,the CD 11b expression in control group obviously higher than those of preopreration(P