BACKGROUND/AIMS: The liver is a central organ in metabolic and irnmune homeostasis under normal and pathologic condition and its funtion is directed by classic homiones and a network of cytokine mediators. Because the liver has a strong potentiol for regeneration, clarifying its mechanism is a matter of great interest. Although many studies on cytokines are being conducted, its clinical significance in hepatectomy still remains unclear. The aim of this study is to clarify the changes of serum cytokines and to investigate the possible regulation of the cytokine release in hepatectomy. METHODS: We studied 55 patients who had underwent hepatectomy in the department of surgery at Yeungnam University Hospital between Septernber 1992 and July 1994. Serum levels of IL-1 0, IL-6, TNF-alpha were measured before operation and on the postoperative day(POD) 1, 3, 5 and 7. Then those were compared between patients with major resection(more than 2 segments) and minor resection, between patients with cirrhosis and those without cirrhosis, and between patients with recovered without complication and patients recovered with comp]ication or inortality. RESULTS: ln the recovery group, the levels of serum IL-10 reached peak levels at POD # 1 and then gradually decreased, the levels of the serum IL-6 reached peak levels at POD 0 l and re- elevated at POD # 5, but there was no significant change in the serial levels of the serum TNF-alpha. No significant difference in the serial levels of cytokines(IL-] 0, IL-6, TNF-alpha) was found hetween the patients with cirrhosis and those without cirrhosis and between the major resection and minor resection. The levels of cytokines in the complication R mortality group were higher than those of the recovery group. CONCLUSIONS: The levels of IL-I 3, IL-6 reached peak level at POD # 1 and gradually decreased to normal levels at POD 0 7 in the recovery group. In the complication and mortality group, the levels of cytokines were higher than those of the recovery group.