Objective To investigate the clinical value of left atrial appendage (LAA) occlusion through transesophageal echocardiography (TEE) guiding in preventing patients with atrial fibrillation from cerebral embolism．Methods 3cases of patients with atrial fibrillation for left atrial appendage occlusion, CHA2DS2VAS score was 2 points or higher. Measured the largest diameter and depth of LAA,Form and function of LAA were observed by TEE before operation.TEE guided interatrial septum piercing, sheath pipe positioning and the release of the closure were implemented in the operation . After the operation,we evaluation effect and follow-up about 45 days by the TEE.Results 3 cases patient of atrial fibrillation successfully completed left atrial appendage occlusion.We used 27 mm diameter Watchman.1 case with 4mm residual shunt,no complication in postoperative follow-up．Conclusions TEE has the important application value in left atrial appendage occlusion between preoperative,intraoperative and postoperatively.It provides technical support for the prevention of cerebral embolism in patients with atrial fibrillation.