Objective To observe the dynamic histopathologic changes of acute rejection in rat orthotopic liver transplantation (OLT) model after tacrolimus discontinued and provide some prediction and evaluation data for clinical acute rejection after liver transplantation. Methods Kamada two-cuff technique was used to establish 60 rat OLT model， and male DA rats, male Lewis rats were used as donors and recipients respectively. Therapeutic amount of tacrolimus (0.05 mg/kg, twice per day, continued for 8 d, 1 d before operation and 7 d after operation, intragastric administrated) was administrated to recipients, then continuously half dose was decreased every day beginning from day 8 after operation and tacrolimus administration was stopped on day 13. Liver tissues were collected on day 7, 14, 21, and 28 after liver transplantation. Histopathologic changes and rejection activity index (RAI) of liver tissues were observed, survival time of recipients was calculated. Results Owing to protection effects of tacrolimus, liver tissues displayed no significant histopathologic changes of acute rejection in 7 d after OLT, while typical acute rejection histopathologic changes began to be observed on day 14 after OLT due to tacrolimus discontinuation. On day 14, 21, and 28, RAI were 3.7±0.9, 6.3±0.9, and 8.1±0.7 respectively. Survival time of recipients was (20.85±0.71) d with a median of 21 d. Conclusion Acute rejection could be induced in rat OLT model after tacrolimus discontinuation, and data collected from this model shows some extent of predictive value and assessment value for clinical liver acute rejection.