Authors had performed experimental study for ventilatory functions & pulmonary hemodynamics following reimplantation of lung. Preoperative & postoperative hemodynamic studies were obtained. A significant reduction in arterial PO2 and PCO2 was observed with the first few days. But these changes returned to near control levels from 1 week after operation in long-term survivors. Also abnormal pulmonary hemodynamic values returned toward control levels within 1 to 3 weeks, with the exception of a residual increase in pulmonary vascular resistance. Microscopically minimal focal pulmonary edema and limited alveolar infiltration developed in the reimplanted lung. But these changes never increased after the their postoperative day and were completely resolved by 1 to 3 weeks after autotransplantation.[KTCS 1977;1:28-37]