Abstract: In the current study, we sought to establish a novel rat model of portal vein arterialization (PVA) and evaluate its impact on liver regeneration after extended partial hepatectomy (PH). A total of 105 Sprague-Dawley rats were randomly assigned to three groups: 68% hepatectomy (the PH group), portal arterialization after 68% hepatectomy (the PVA group), and right nephrectomy only (the control group). Liver regeneration rate (LRR), 5-bromo-2-deoxyuridine (BrdU) labeling index, and liver functions were assessed on postoperative day 2, 7, 14 and 28. The 28-day survival rates were compared among the three groups. The 28-day survival rates were similar in all groups (P 5 0.331), and the anastomotic patency was 100%. The LRR in the PVA group was significantly higher than that of the PH group within postoperative 14 days (P , 0.05). The PVA and PH group had increased serum alanine aminotransferase levels (232 ? 61 U/L and 212 ? 53 U/L, respectively) compared with the control group (101 ? 13 U/L) on postoperative day 2, whereas from postoperative day 7 to day 28 there were no differences among the three groups. Serum albumin values were higher after the PVA procedure within postoperative day 14, which gradually became comparable on postoperative day 28 among the three groups. The peaks of BrdU labeling index appeared on postoperative day 2 in all rats, and the PVA procedure was associated with increased BrdU labeling index from postoperative day 7 to 28. The 28-day survival of the PVA rats was comparable. Our findings demonstrate that the PVA procedure utilizing portal vein trunk-renal artery microvascular reconstruction promotes remnant liver regeneration and confers beneficial effects on maintaining and even optimizing liver function after extended partial hepatectomy in rats.