A one-year-old infant with congenital mitral stenosis and pulmonary hypertension underwent by mitral valve replacement with his pulmonic valve autograft and pulmonary tract reconstruction with heterogeneous pericardial conduit. His postoperative hemodynamics data showed that left atrial pressure decreased and pulmonary hypertension continued. Echocardiography showed that the implanted autograft functioned properly. On the seventh postoperative day, he died of pulmonary hypertension. In case with congenital mitral stenosis with the small mitral annulus and the small left ventricular cavity, it is difficult to perform mitral valve replacement by commercially available mechanical or tissue valves. Because these valves are not suitable for the small mitral annulus. The mitral valve replacement with pulmonic valve autograft is recommended in such a case with the congenital mitral stenosis.