Objective:To investigate the changs of cell adhesion molecules and observe the influence with ulinastatin during the infant cardiopulmonary bypass. Methods:Sixty infants with congenital heart disease were randomly divided into two groups:group U(received ulinastatin 20 000 U/kg,dissolved in 20 ml normal saline),group C(received 20 ml normal saline). Blood samples were collected in different moments. The proteinum expressions of ICAM-1 and CD11b/CD18 were examined,and the variations were observed. The blood gas value and calculated respiratory index(RI) were also detected. Results:The expressions of ICAM-1 and CD11b/CD18 increased significantly after CPB in two groups with RI rising,and increased more obviously in group C than those in group U(P < 0.05). Conclusion:The expressions of ICAM-1 and CD11b/CD18 increased,and RI rose during the CPB in infant. Ulinastatin may relieve the process.