This is report of two cases of annular constrictive pericarditis. Since January 1959 to December 1979 the authors experienced 48 cases of chronic constrictive pericarditis treated surgically at the Department of Thoracic and Cardiovascular Surgery, the National Medical Center in Seoul. These cases simulated valvular heart disease. One case, as mitral stenosis, revealed rumbling apical diastolic murmur [II/VI], atrial fibrillation and right ventricular hypertrophy pattern on E.C.G., the other, as infundibular pulmonic stenosis, presented pressure gradient between right ventricle and main pulmonary artery at infundibular level of 76 mmHg in systole. Both patients underwent operation successfully and one of them was assisted by E.C.C. during pericardiectomy and result was excellent. It is difficult to make the diagnosis of these conditions preoperatively so consideration about these might be important to make the diagnosis accurately.