Objective To observe the pathophysiological change of right heart remodeling model of beagle dogs caused by tricuspid regurgitation. Methods Six beagle dogs were separated to TR group and sham operation group randomly and equally. The anterior and posterior leaflets of tricuspid valve of beagle dogs from TR group were cut off under direct vision on the beating heart. The echocardiography data were measured pre-operation and post-operation 3, 6, 12 months respectively and autopsy results were acquired after the sacrifice of two animals who had been raised for 18 months. Results The operation was successful and survival 100%. The weight of TR group increased, and the echocardiography showed right atrium and ventricle enlargement and right heart dysfunction. The autopsy of TR group found myocardial fibrosis , liver cirrhosis and ascites. All of the results indicated the occurrence of right heart remodeling and right heart failure. There is no significant difference in sham operation group before or after operation. Conclusion The myocardial fibrosis is one of the pathological basis of right heart remodeling.