Objective To establish and improve the abdominal heterotopic heart transplantation model in mice, so as to provide references for the research on organ transplantation immunology. Methods C57BL/6 mice were selected as donors and recipients for syngeneic cardiac transplantation and recipients for allogeneic cardiac transplantation; BALB/c mice were selected as donors for allogeneic cardiac transplantation. The ascending aorta and pulmonary artery of the heart of the donors were end-to-side anastomosed with the abdominal aorta and inferior vena cava of the recipients, respectively, to establish abdominal heterotopic heart transplantation models in mice. Furthermore, the techniques of preparing recipient heart before implantation, extracting and preparing donor heart, and vascular anastomosis were improved, and the surgical results and advantages were observed and analyzed. Results Preliminary experiments were performed on 50 pairs of mice. For formal experiments, syngeneic cardiac transplantation was performed on 20 pairs and the success rate was 85.0% (17/20); allogeneic cardiac transplantation was performed on 15 pairs and the success rate was 86.7% (13/15). The total success rate of abdominal heterotopic heart transplantation was 85.7% (30/35). The average time for preparing recipient before vascular anastomosis was (11.2±2.5) min, the average time for extracting and preparing donor heart was (13.6±3.3) min, and the average time for vascular anastomosis was (21.7±3.5) min. Conclusion The improved abdominal heterotopic heart transplantation model in mouse has the advantages of easy-to-perform and high success rate, which lays a foundation for the further study of transplantation immunology.