Objective:To study the protective effect and mechanism of anisodamine on cardiopulmonary bypass(CPB) induced lung injury. Methods:According to the medicine dose and administer time,twenty four patients with congenital heart defect (CHD) were divided into four groups. Control group, group Ⅰ(anisodamine 2 mg/kg, priming solution),group Ⅱ(anisodamine 2 mg/kg,main pulmonary artery), group Ⅲ(anisodamine 1mg/kg,priming solution + anisodamine 2 mg/kg,main pulmonary artery). Neutrophil,CD11b and TNF-a were measured at five time points of the operation. Little lung tissue was cut out for detecting NF-κB after the operation. Blood gas analysis were also arranged. Results:The level of neutrophil,CD11b and TNF-α was reduced in group Ⅰ, group Ⅱ and group Ⅲ compared with the control group, especially in group Ⅱ and group Ⅲ. The results of NF-κB was conformity with the former. Certinary blood gas analysis changed better. Conclusion:CPB induced lung injury can be protected with anisodamine, and the gomphosis pathway(administer through priming solution and main pulmonary artery) is better. The protective mechanism may be that anisodamine inhibits the activation of NF-κB.