The liver function during operation is influenced by several factors. These factors include preoperative condition of the patient, site and durstion of the operation, operation per se. and anesthetic agents. Recently, there have been many controversies about hepatic dysfunction of the halogenated inhalation: anesthetics. This study was done to evaluate the hepatic dysfuncson by comparison of pre-and: postoperative liver dysfunction in randomized selection of 127 cases arnong 495 elective operations. As results, 1) There was increased tendency of post-operative 48 hour s-GOT in balanced anesthesia group. 2) After prolonged operation, there was more tendency of marked elevation of LFT values. 3) The elevation of s-GOT was also noted in adult low-weighted person. 4) In the cases of intraabdominal operation, changes of LFT were more prominent than the operation of the other site. 5) Choice of anesthetic agent alone is not enough to prevent hepatic dysfunction during operation.