Background: Changes in hepatic oxygen metabolism in relation to the extent of liver regeneration are expected after partial hepatectomy. There are few reports, however, about hepatic oxygen metabolism during liver regeneration. In this study, we evaluated changes in hepatic oxygen metabolism related to the regeneration rate, and the relationship between hepatic venous oxygen saturation (Shvo 2) and liver regeneration after partial hepatectomy. Methods: The work was done using 50% hepatectomized rats with continuous infusion of octreotide for inhibition of liver regeneration or with saline as control. The hepatic hemodynamics, oxygen metabolism, and Shvo 2 levels as well as the regenerating liver status were evaluated for 3 days after hepatectomy. Results: Administration of octreotide resulted in a significant reduction of the regenerating liver weight on days 1 and 3 after hepatectomy compared with the control group. Significantly decreased DNA synthesis and proliferating cell nuclear antigen labeling index were also found on day 1. Meanwhile, hepatic oxygen consumption (HVO 2) and oxygen extraction ratio were significantly decreased in the octreotide-treated group on day 1. In contrast, the Shvo 2 levels in the octreotide-treated group were significantly higher than those in the control group, and were inversely correlated with the HVO 2. Conclusion: The remnant liver demands an increased amount of oxygen in relation to the extent of regeneration, and changes in the Shvo 2 are inversely correlated with the HVo 2. Therefore, monitoring the Shvo 2 could be useful for estimating liver regeneration after partial hepatectomy.