Objective: Objective to investigate the causes of residual shunt after transcatheter closure of percutaneous left atrial appendage by transesophageal echocardiography (TEE) and to guide the release of occluder. Method：In January 2014 -2015 December, 54 patients with atrial fibrillation in Wuhan Asian heart hospital were successfully treated with left atrial appendage with Watchman occluder. The maximum opening and maximum depth of left atrial appendage were measured at TEE0, 45, 90 and 135 degrees before operation. The shape and position of occluder were observed immediately and 45 days after the operation. The diameter of the occluder was measured and the compression ratio was calculated. Result：1) there was no residual shunt during and after operation in 51.8% (28/54) patients; residual shunt was found in 29.6% (16/54) patients (< 5mm), and residual shunt still existed after 45d review (<5mm); 18.5% (10/54) had no residual shunt during operation, and residual shunt (<5mm) was found after operation 45d;2) TEE135 degree scan is more sensitive than other angles to detect residual shunt; 3) all patients had no cerebrovascular or other vascular embolism, 3 cases of pericardial effusion appeared in the operation, no pericardial effusion was found in 7d reexamination after operation, and thrombus appeared on the surface of occluder after 45d reexamination in 2 cases. Conclusion: Transesophageal echocardiography plays an important role in the follow-up of left atrial appendage occlusion.