OBJECTIVE： To investigate the protective effects of insulin-glucose on myocardium in patients receiving cardiac valve replacement under cardiopulmonary bypass. METHODS： Totally 120 patients receiving combined cardiac valve replacement under cardiopulmonary bypass were divided into control group and observation group according to random number table， with 60 cases in each group. All patients were given routine operation. Control group was given Thomas cardioplegia and oxygenated blood with a ratio of 1 ∶ 4 （V ∶ V）to protect myocardium at 4 ℃. Besides that， the observation group was additionally given Insulin injection 10 IU/L and Glucose injection 10 g/L added into Thomas cardioplegia at 4 ℃ to protect myocardium. The levels of plasma brain natriuretic peptide （BNP） and cardiac troponinⅠ（cTnⅠ）before anesthesia induction （T0）， at the end of cardiopulmonary bypass （T1），12 h （T2），24 h（T3），48 h （T4）， and 72 h （T5） after surgery， the rate of recovery of automatic heartbeat after opening aorta， the application of vasoactive agent （dopamine） at T1 and the occurrence of postoperative complications were observed and compared between 2 groups. RESULTS： At T0， there was no statistical significance in the levels of plasma BNP and cTnⅠ between 2 groups （P＞0.05）. The levels of plasma BNP and cTnⅠin 2 groups at T1-5 were significantly higher than T0， with statistical significance （P＜0.05）； the levels of cTnⅠ began to decrease at T4 and cTnⅠbegan to decrease at T5. However， the levels of BNP and cTnⅠwere significantly lower in observation group than in control group at T1-5， with statistical significance （P＜0.05）. After opening aorta， there was no statistical significance in the rate of recovery of automatic heartbeat between 2 groups （P＞0.05）. The dosage of dopamine （at T1） and the incidence of complications in observation group were statistically lower than control group， with statistical significance （P＜0.05）. No severe ADR was found in 2 groups during or after surgery. CONCLUSIONS： Insulin-glucose can alleviate myocardial damage，  reduce the dosage of vasoactive agent and the incidence of postoperative complications in patients receiving combined cardiac valve replacement under cardiopulmonary bypass with significant protective effect on myocardium with good safety.