Abstract： Objective To explore the effect of telmisartan (TMST) on experimental swine models with atrial fibrillation (AF) , and to isolate and identify the target proteins expressed in right atrial myocardium.Methods Eighteen healthy pigs were randomly divided into three groups (n=6 each). Electrodes were implanted in the swines of three groups, with no pacing in control (NC) group, rapid atrial pacing (RAP) in the experimental AF model (AF group) and RAP plus telmisartan (TMST) intervention in the TMST group. Left and right atrial end-systolic areas (LAESA, RAESA) were measured by ultrasonic cardiogram before and 2 weeks after experiment. At the end of study, the histological change of right atrium was studied with Masson staining, and differentially expressed proteins of right atrium were isolated by twodimensional polyacrylamide gel electrophoresis (2-DE) ,and target proteins were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry(MALDI-TOF-MS). Results The AF model was successfully established with RAP.Compared with AF group, the TMST group had less induction rate of AF and collagenous fiber, and significantly reduced LAESA and RAESA [LAESA: (630.6±10.9) mm2 vs(744.3±29.9)mm2; RAESA:(553.4±13.7) mm2 vs (677.9±26.3) mm2, all P＜0.05]. Three proteins (eukaryotic translation initiation factor 5A, heat shock protein 27 and NADH dehydrogenase Fe-S protein 8)showed declined expressions in the right atrial myocardium of TMST group. Conclusion Eukaryotic translation initiation factor 5A, heat shock protein 27 and NADH dehydrogenase Fe-S protein 8 may be target proteins associated with reduced induction rate of AF and inhibition of atrial remodeling by TMST intervention.