Objective：To analyze changes of protein expression in rat transplant kidney by proteomics technique and to search and identify differential expression proteins which are related with acute rejection. Methods：All transplant rats were divided into two groups： experimental group（F344→Lewis） and control group（F344→F344）. Rat models of allogene renal transplantation were estab－lished respectively and allograft specimens were obtained on 7 d post the transplantation. Total proteins of rat transplant renal tissues were separated by two-dimensional gel electrophoresis（2-DE）. Differential expression proteins were analyzed and then identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry（MALDI-TOF-MS）. Results：Averages protein spots in ex－perimental group and control group were 554.0±34.0 and 542.0±21.0 respectively. Compared with those in control group，37 dif－ferentially expressed proteins were screened in experimental group，of which 29 were identified by peptide mass fingerprint and 6 were founded by bioinformatics in SwissProt data base. Conclusion：Six differential expression proteins which may correlate with acute rejection of renal allograft are identified by comparative proteomics and might become possible biological marker of acute rejection of renal allograft.