We have experienced two cases of one lung anesthesia using univent tube for thoracie surgery. One was the bronchoplasty of the right upper lobe. The other was the left pneumonectomy. The movable endobronchial blocker was introduced into the aimed main bronchus applying the "tube rotation method", In the case of brochoplasty, arterial hypoxemia and hypercarbia has not been corrected well because of the partial obstruction of the carina by endobronchial blocker, but the neurologic complications due to these problems were not encountered. No significant problem has been encountered in the pneumonectomy case. Compared with the standard technique using a double lumen endobronchial tube, this method is simple, easy, effective and less traumatous.