A clinical study was made on 434 patients of valvular heart disease admitted to the Seoul National University Hospital during the period of November 1971-February 1978. The results were obtained as follows: 1) The number of valvular heart disease was 434 patients, which accounts for 2.6% of the total hospitalized patients during the same period. The sex incidence of valvular heart disease were female 48.6%, male 51.4%. The incidences of each valvular heart disease were mitral stenoinsufficiency 31.8%, mitral stenosis 24.2%, mitral insufficiency 21.0%, combined valvular heart disease 12.2%, aortic insufficiency 7.1%, aortic stenoinsufficiency 1.6%, pulmonic stenosis 1.4%, and aortic stenosis 0.7%, in order. 61.5% of all were in third to fifth decade in age distribution. 2) The following were found as etiological factors: rheumatic fever 36.4%, atherosclerosis 1.6%, syphilis 0.9%, and unknown and others 61.3%. 3) The main subjective symptoms were dyspnea, palpitation, cough, orthopnea, sputum, chest pain, fatigue, blood tinged sputum, dizziness, and headache. And the main objective finding were hepatomegaly, venous engorgement, edema, pulmonary congestion, thrill, ascites, splenomegaly, malar flush, and finger clubbing. 5) The disturbance of liver function were found in about 30% of valvular heart disease. 6) The abnormalities of electrocardiographic findings were observed as follows: atrial fibrillation 55.1%, ventricular premature beat 15.2%, first degree atrioventricular block 8.5%, incomplete right bundle branch block 4.1%, complete right bundle branch block 1.4%, second degree atrioventricular block 0.9%, and left bundle branch block 0.9%, in rhythm and conduction disturbance, and left ventricular hypertrophy 44%, right ventricular hypertrophy 18.2%, biventricular hypertrophy 4.6%, left atrial enlargement 19.8%, and right atrial enlargement 3.2%, in chamber enlargement.