Liver has a strong potential for regeneration, and its mechanisms is a matter of great interest. It has been proved that hepatocyte growth factor(HGF) is the most potent stimulator of DNA synthesis in the mature hepatocyte. We evaluated the influence of hepatectomy on serum HGF levels. We examined 10 hepatectomized, using, 10 gastric resected patients as control. The HGF levels of malignancy is higher than that of benign disease and the HGF levels of hepatoma and Klatskin tumor is higher than that of stomach cancer. The correlation between serum bilirubin. ALT and HGF was significant were but not in arterial ketone body ratio. In the hepatectomized group, HGF levels were elevated significantly on the 1st postoperative day compared with the preoperative value. On the 5th day, hHGF levels in the hepatectomized group were significantly higher than those in the gastric resection group. We conclude that the higher levels of malignancy seen compared to benign disease suggests that HGF may be related to cancer biology. The serum HGF levels rapidly increased after hepatectomy, suggesting that HGF may have an important role in liver regeneration but elevation of HGF is not specific to the liver. The implication of the linear correlation between serum bilirubin and HGF needs to be investigated further.