Abstract: Abstract Objective：To assess the clinic value of transesophageal echocardiography(TEE)during cardiac valve surgery．Method：To monitor 247 patients undergoing cardiac valve surgery in order to compare the results with pre-operative conditions and observe retained air.Result： (1)Additional defect was found in 29 cases(11.74％).Pre-operative diagnosis was found to be wrong by TEE in 20 cases(8.09％).(2)There was significant improvement in the mitral regurgitation grade after mitral replacement(P<0.01).Significant residual mitral regurgitaton(＞grade3) that necessitated immediately further surgery was identified in 5(2.5%） patients.The results for re-do were satisfactory.(3)The left atrial gas was detected in 188(76.11%) patients among 247 cases.Conclusion:Intra- operative transesophageal echocardiography is useful in supplementing pre-operative diagnosises and assessing immediate operative results or identifying retained air.

Key words: Echocardiography, transesophageal, cardiac valve surgery, Anaesthesia, intraoperative