Ｏｂｊｅｃｔｉｖｅ　To discuss the effects of preoperative use of recombinant human erythropoietin (rHuEPO) on inflammatory lung injury patients after cardiopulmonary bypass (CPB) under extracorporeal circulation. 　Methods　A total of 54 patients who were scheduled to receive elective open cardiac operations under CPB were enrolled. They were divided into two groups(n=27). rHuEPO group: patients were titrated intravenously with rHuEPO (100 IU/kg, diluted into 50 ml normal saline) for consecutive three days at the same time period before operation. Control group: equivalent normal saline in place of rHuEPO was given to patients via venous injection. Peak airway pressure (Ppeak), plateau pressure (Pplat), and pulmonary dynamic compliance (Cdyn) were well monitored and recorded before CPB (T1), immediately after chest closure (T2), and 2, 4 h and 6 h after surgery (T3, T4, and T5). At T1, T2, T5, and 12, 24, 48 h, and 72 h after surgery (T6, T7, T8, and T9), arterial oxygenation indices (OI) were also recorded. Furthermore, at pre-rHuEPO treatment (T0), T1, T2, T5, T6, T7, T8, and T9, the plasma levels of the tumor necrosis factor (TNF)-α and interleukin (IL)-1β and IL-10 were measured. The time of mechanical ventilation and stay in intense care unit (ICU), discharge time and hospitalization stay were also recorded.　Results　Compared with the control group, Cdyn in the rHuEPO group at T2-T5 were significantly increased (P<0.05), whereas Ppeak and Pplat were decreased (P<0.05). OI values of rHuEPO group at T2 and T5-T9 were significantly higher than that of control group(P<0.05). It was demonstrated that at any time point after closing chest, the plasma concentrations of TNF-α, IL-1β, and IL-10 in both groups were relatively elevated compared with those before, while the concentrations of TNF-α and IL-1β in the rHuEPO group were lower than those in control group (P<0.05). Compared with the control group, patients receiving rHuEPO treatment underwent an apparent reduction in both mechanical ventilation and staying time in ICU (P<0.05). 　Conclusions　Preoperative rHuEPO administration can attenuate the inflammatory lung injury after CPB via the anti-inflammation pathway and ameliorate pulmonary functions.