Objective To investigate the early clinical effects of using transesophageal echocardiography(TEE) in order to guide percutaneous transcatheter closure of atrial septal defect in children in comparison to fluoroscopy. Methods From Oct.2012 to Jan.2014, 50 cases of consecutive children(TEE group) undergoing percutaneous transcatheter closure of atrial septal defect received the procedure completely guided and monitored by TEE.One hundred and sixty-two children who guided by conventional fluoroscopy during the same period served as controls.After 1 month of the operation, patients of 2 groups were followed up by conducting transthoracic echocardiography. Results The mean age, mean body weight, the mean size of atrial septal defect and occlusion, procedure time, and hospital stay time had no statistical differences between 2 groups.In comparison with the TEE group and control group, there were no differences in the rate of successful occlusion(100.0% vs 97.5%, P=0.58) and immediate postoperative residual shunt(0 vs 4.4%, P=0.20). The TEE group required general anesthesia intubation time lasted (2.9±0.5) h and the control group was spontaneously breathing under sedation.During 1 month follow-up, there were no complications such as residual shunt, peripheral vascular injury, cardiac perforation or occluder abscission in all patients. Conclusions Percutaneous transcatheter closure of atrial septal defect completely guided by TEE is safe and minimally invasive in children.The procedure can avoid the injuries of radiation and contrast agent.Its effect can compete with that by using traditional fluoroscopy. Key words: Atrial septal defect; Echocardiography; Transesophageal; Heart catheterization; Child