Abstract： Objective To investigate the reliability of intramyocardial electrogram (IMEG) in monitoring acute rejection after human heart transplantation. Methods From June 2004 to March 2009, 32 patients underwent orthotopic heart transplantations. During the operation telemetric pacemakers were placed under the skin of the body with connected bipolar electrodes implanted into epimyocardium. Postoperative IMEGs, including the autonomous IMEG and ventricular evoked response (VER) were recorded routinely. The endomyocardium biopsy (EMB) was taken routinely and performed once again when positive IMEG results or other positive signs were observed. Results Totally 523 IMEGs has been produced, 41 of VERs were recorded together with autonomous IMEGs and EMBs, in which 17 EMB specimens were confirmed positive and 24 negative. AUC of QRS was 0.7537, Se was 88.24%, Sp was 62. 50%; AUC of Tslew was 0. 9081, Se was 94. 12%, Sp was 87. 50%. QRS and Tslew had significant difference in AUC of ROC, with x2 = 4. 22, P＜0. 05; AUC of combined diagnostic index (positive when either QRS or Tslew is positive and negative when both values are negative) was 0. 7917, Se was 100.00%, Sp was 58. 33%. Conclusion QRS amplitude of the autonomous IMEGs, Tslew of VERs and combined diagnostic index are reliable indexes for monitoring acute allograft rejection after human heart transplantation. Furthermore, Tslew has a better prognostic value than QRS.