Of the valve replacement patients operated between 1983 and June, 1984, 75 patients need more than 60 minutes of aortic cross-clamping time. 42 patients performed single valve replacement [35 MVR, 7 AVR with or without TAP] and remainder needs double valve replacement with or without TAP. The average aortic clamping time was 95.1 minutes. They need 30 minutes more extra-corporeal circulation time than aortic clamping time. The patients were divided into two groups by usage of cardioplegic solution. Group I [n=31] with Bretschneider solution and group II with potassium cardioplegic solution [M.G.H. modification] were analyzed by extra-corporeal circulation data,/CG and Echocardiography findings, and clinical data. There was no difference between two groups in Bivon addition amounts [cc/kg] and E.F. and S.F. by echocardiography, group I need 1 more electrocardioversion to convert sinus rhythm postoperatively. Also no difference could be found in patients whose preoperative C.I. was above 2.0 between two group. But significant postoperative decrease in E.F. was found in group I whose preoperative C.I. was below 2.0. Relatively longer ECC time was also needed in same group. Ischemic changes in ECG and low cardiac output syndrome was, however more prevalent in groupII. As a whole, the clinical data was satisfactory with both cardioplegic solution in clinical practice.