ABSTRACT Objective To analyze and explore the value of transesophageal echocardiography in perioperative period of adult aorto ventricular tunnel . Methods The results of echocardiography and clinical features of 11 patients who had been diagnoesed as aorto ventricular tunnel were retrospectively analyzed, and 10 cases were compared with the surgical，2 cases were detected by pathology. Results There were 2 cases of ALVT with type I 、4 cases of ALVT with typeⅡ、3 cases of ALVT with typeIII and 1 case of ARVT. Pathological examination of 1 case of ALVT type II and 2 cases of ALVT type III showed that the cystic of the channel was fibrous tissue hyperplasia with focal myxosis and necrosis, and the tissue around the aortic valve was extensive hyaline degeneration with acute inflammatory change. Suture, patch and prosthetic valve replacement were performed according to the severity of each lesion and associated malformation. 3 patients with ALVT underwent secondary operation due to perivalvular leakage and / or avulsion of patch, and 1 patient (with infective endocarditis) died of heart failure after the second operation. ALL the other patients have a good prognosis. The diagnostic accuracy of TEE is higher than TTE and CT. Real-time three-dimensional can provide more intuitive and vivid information, and islice is better than other imaging mode in lesion detail. The correlation between the measurement of two-dimensional TEE and operation is the best. Conclusion TEE is better than TTE and CT in preoperative diagnosis，intraoperative monitoring and postoperative follow-up of aorto ventricular tunnel .