Objective To explore the clinical application value of transesophageal echocardiography（TEE） in perioperative period of adult aorto-ventricular tunnel.Methods The results of echocardiography and clinical features of 11 patients who had been diagnosed as aorto-ventricular tunnel were retrospectively analyzed

the diagnostic accuracy of TEE was calculated. The correlation between echocardiography and intraoperative measurement in estimating the lesion and their openings were analyzed.Results Among the 10 cases

there were 2 cases of aorto-left ventricular tunnel（ALVT）with type Ⅰ

4 cases of ALVT with type Ⅱ

3 cases of ALVT with type Ⅲ and 1 case of aorto-right ventricular tunnel（ARVT）. Three patients with ALVT underwent secondary operation due to perivalvular leakage and/or avulsion of patch

and 1 patient died of heart failure after the second operation. The rest two patients had a good prognosis. Among the patients treated by surgery

the diagnostic accuracy of TEE was higher than that of TTE and CT

and the accuracy of TEE

TTE and CT were 100%

60% and 57%

respectively. The average diameter of the entrance of the channel were（5.75±3.76）mm and（5.96±3.84）mm

the average diameter of the outlets of the channel were（5.15±1.81）mm and（5.53±1.89）mm

the correlation between the measurement of two-dimensional TEE and operation was best（r=0.99

0.88

both P<0.05）.Conclusion TEE has important clinical application value in preoperative diagnosis

intraoperative monitoring and postoperative follow-up of aorto-ventricular tunnel.