Abstract: Objective: In order to improve the long term survival of renal allograft, a study on rejection and expression of Bcl-2 in renal allografts was designed in this series. Methods: Immunohistochemical determination using antibodies for Bcl-2 gene protein were performed in 6 cases of acute rejection, 3 cases of chronic rejection, and 1 case of cytomegalovirus infection. Two cases of acute rejection and two cases of chronic rejection were studied by transmission electron microscope to confirm apoptosis. Results: On the tubules stain for Bcl-2, it showed that a more positive density was found in control group comparing with allografts （P＜0.01）. Under electron microscope, apoptosis were demonstrated. Conclusion: Detection and localization Bcl-2 expression may act as morphological characteristics to monitor the renal allograft.