Background　Lung injury after cardiopulmonary bypass（CPB） is a severe complication of cardiac surgery， which is closely related to the rate of heart surgery and postoperative mortality. The effect of pulmonary surfactant-associated protein A（SP-A） in lung injury after CPB has been paid more attention by scientists recently.　Objective　To provide theoretic basis for clinical and basic， were reviewed the research process of the effects of SP?蛳A in lung injury after CPB.　Content　Molecular structures， genes， receptors， regulation and physiological role of SP-A and the research process of effects of SP-A in lung injury after CPB were all reviewed.　Trend　With the development of molecular biology techniques， cloned or synthetic human SP-A， and the help of construction of vector for eukaryotic cells in vivo expression， SP-A become a new direction of treatment of lung injury after CPB.