Objective:To study management of hyperkalemiaduringcardiopulmonary bypass.Methods:82 patients with hyperkalemia during CPB were divided into two groups:ultrafiltration and insulin.Results:The serum potassium concentration in ultrafiltration and insulin were dropped to 5.1 (3.4 ~ 5.6)mmol/L.Conclusion:Ultrafiltration method was suitable for critical patients undergoing valev replacement surgery.Insulin was suitable to the patients with serum potassium concentration more than 6.5mmol/L and immediately before release of aortic.But hypokalemia and hypoglycemia should be prevented.