Objective: To observe the liver function and histological alterations in rats after portacaval transposition (PCT). Methods: Seventy-two male SD rats were equally randomized into experimental group and control group. Rats in experimental group underwent PCT operation by end-to-end anastomosis of the proximal portal vein to the distal inferior vena cava, and end-to-end connection of the distal portal vein to the proximal inferior vena cava, while rats in control group underwent transient blood flow blockage of the portal vein and inferior vena cava for the same periods of the anhepatic phase as their counterparts in experiment group. At 6, 12 and 24 h, and 3, 7 and 28 d after surgery, 6 rats in each group at each time point were sacrificed, respectively. The serum levels of alanine aminotranferease (ALT) and aspartate aminotransferase (AST) in rats of the two groups were measured, the pathological examination and hepatocyte apoptosis assay of liver tissues were performed and the expression of the proliferating cell nuclear antigen (PCNA) in the liver tissues were also determined. Results: The serum levels of ALT and AST in rats of experimental group were significantly higher than those of control group at 6 and 12 h after operation (all P<0.05), both of which presented a declining trend and showed no significant difference with those of control group at 3, 7 and 28 d after operation (all P>0.05). The pathological examination showed that the liver tissues in control group were generally normal, and in experimental group showed mild pathological changes such as cellular swelling, spotty necrosis and small amount of inflammatory cell infiltration, which were most evident at 6 h after operation. A small amount of apoptotic liver cells were seen in both groups at each observation time points, but no significant difference was noted in the apoptotic index (AI) between the two group (all P>0.05). The PCNA expressions in the livers of experimental group were significantly higher than those of control group at 24 h, 3 and 7 d after operation (all P<0.05), but were decreased at 28 d after operation and showed no difference with that of control group (P>0.05). Conclusion: PCT can cause a certain degree of liver impairment in short-term of postoperative period, but it may not exert obvious impact on cell proliferation and apoptosis of the liver in long-term period.