Objective:To investigate the significance of arterial reconstruction on the model of 40% small-for-size orthotopic liver transplantation in rats. Methods:Modified two-cuff technique was applied to establish a rat model of 40% orthotopic liver transplantation. A total of 192 sprague dawley (SD) rats were randomly divided into 2 groups:small-for-size orthotopic liver transplantation with arterial reconstruction group (A group) and small-for-size orthotopic liver transplantation without arterial reconstruction group (B group). One week survival rate,main indexes of liver function,histology and the expression of the proliferative cell nuclear antigen (PCNA) of liver graft by immunohistochemical method were detected on the 1st,2nd,4th and 7th day after transplantation,respectively. Results:One week survival rate of A group and B group were 66.7% and 50.0%,respectively (P > 0.05). Alanine aminotransferase (ALT) and total bilirubin(TB) began to elevate from the first day and peaked on the second day after surgery. ALT in B group on the second and fourth day were higher significantly than those in A group(P < 0.05). TB in B group on the second and seventh day were higher significantly than those in A group(P < 0.05). Histological findings indicated that more diploid and polyploid hepatocytes could be seen in A group. The expression of PCNA of liver graft peaked on the 2nd day after surgery. The expression of PCNA in A group was higher on the 1st day and lower on the 7th day than that in B group after operation(P < 0.05). Conclusion:Arterial reconstruction can improve liver function of liver grafts after small-for-size orthotopic liver transplantation,and alleviate the histological changes and promote the regeneration of liver grafts quickly.