Abstract Objective: To investigate the methodological improvement and process optimization of 50% reduced-size liver orthotopic transplantation model in rats. Methods: Base on the classical double-bushing model, establish new process to improve the effect of liver resection, with the method of penetrated puncture 4 rounds, ligate 3 times and 2 folds back to graft the 50% reduced-size donor liver orthotopically. Results: All rats remain good conditions after operation, liver function keep back to normal level quickly. Conclusions: With the surgical novel graft method, a stable 50% reduced-size orthotopic liver transplantation model could be established，and meet the requirement of design of experiment of animal model.