Abstract： Objective To evaluate protective effects of hypothermic pulmonary protective solution with uli-nastatin on lung function during cardiopulmouary bypass (CPB) in the patients with congenital heart disease(CHD) and pulmonary hypertenion. Method Fifty-four children,who had CHD of left-to-fight shunts with moderate-se-rious pulmonary hypertension, were enrolled. They had been performed with the radical operation under CPB from September 2005 to December 2006 in the Department of Cardiovascular Surgery, Children' s Hospital of Zhejiang University. Moderate-serious pulmonary hypertension was defined as pulmonary-to-systolic pressure ratio > 0.45(Pp/Ps > 0.45). Fifty-four children were randomly divided into three groups. Patients in group A (n = 18)didn't receive pulmonary protective solution, and scrved as control; patients in group B (n = 18) were adminis-tered with pulmonary protective solution without ulinastatin;patients in group C (n = 18) were administered with pulmonary protective solution with ulinastatin. The serum concentrations of MDA and MPO were measured at five different time points:pre-operation, 0 h, 3 h, 6 h and 24 h in the intensive care unit (ICU) (T1～5). Patients'lung functions were monitored at T1 - T4. The time of mechanical ventilation was recorded. Results No one died in this study. The mean time of mechanical ventilation was shorter in the group B and group C than that in the group A. The MDA and MPO levels were lower in group B compared with group A at T4. The MDA level at T3-T5 and the MPO level at T4 was lower in group C than those in group A. There were no significant in MDA and MPO levels between group B and group C at five time point.A-aDO2 was lower in groups B and C than those in group A at T3 and T4, whereas at T4, A-aDO2 was lower in group C than that in group B. Cdyn was higher in group B at T3and group C at T3 - T4 than those in group A. Cdyn was lower in groups C than that in group B at T4.Condusions Lung perfusion with hypothermic protective solution during CPB can all lung injury and promote recovery after operation, especialy with ulinastatin.