One hundred eighty-eight patients[August.23,1988,through July.30,1994 underwent aortic[AVR , mitral[MVR , or double [DVR valve replacement with the St.Jude Medical prosthesis. The author analyzed 100 patients with valvular heart disease,who underwent valve replacement with the St.Jude Medical prothesis from 1990 to 1994, at Hanyang University hospital Cardiovascular department. Information on volume and functional change of the heart chamber can be obtained by cardiac echocardiography and cartheterization. Out of 100 patients, 40 patients were male[40% and 60 patients were female [60% . Age ranged from 13 years to 68 years, with mean age of 42.6 years. Mean height was 160.3cm and mean body weight was 54.9Kg. According to NYHA functional classification, class III is most frequent and 60 patients could be classfied under it. MVR [involved Redo MVR was performed in 40 patients, AVR [involved Redo AVR was performed in 18 patients, and DVR [involved Redo DVR was performed in 42 patients. Warfarin [Coumadin anticoagulation was recommended for all patients. Life long warfarin anticoagulation was necessary to all patients who underwent valve replacement with St.Jude Medical prosthesis. Ideal prothrombin time was maintained about 30% during warfarinization. There were no case of mechanical failure. It followed a comparison of echocardiography before and after valve replacement at Hanyang University hospital [30 patients and a preoperative evaluation of cardiac catheterization and angiography [64 patients . The St.Jude Medical cardiac valve is a viable alternative in the surgical therapy of valvular heart disease.