We have performed four left lung reimplantation and right pulmonary artery ligation in dogs for six months from March 1989 to September 1989 at the Thoracic & Cardiovascular Surgery department, Yonsei University, College of Medicine, Seoul, Korea. Excised left lungs were perfused with 200cc of 4oC cold saline at a pressure of 60cmH2O through left pulmonary artery & preserved in 4 oC cold saline for about 20 mins. Left lung reimplantation were proceeded with inferior pulmonary vein, superior pulmonary vein, left pulmonary artery and left main bronchus in order. The main pulmonary artery pr. were 39/21[31], 22/12[15], 25/9[15] and 54/17[37] mmHg each after right pulmonary artery ligation on left reimplanted dogs, Right pul a. ligations were performed 9 days, 12 days, 16 days and 19 days after left lung reimplantation. Two dogs died at 10 days 21 days, after right pul. a. ligations in left reimplanted dogs. The remaining two dogs were sacrificed at 18 days, 21 days after right pul. a. ligation in left reimplanted dogs. Autopsy findings showed narrowing of left superior pul. vein anastomotic site in two narrowing of left pulmonary artery anastomotic site in one narrowing of left sup. pul vein & pneumonia of left lung in one. In the lung transplantation, it was thought to be important that the anastomosis of pulmonary artery and especially pulmonary vein be done with particular precaution for early and late stenosis.