Abstract: Objective: To evaluate the value of transthoracic echocardiography (TTE) in transcatheter closure of congenital heart diseases patients choice before operation,monitoring in operation and observation treatment effect after operation.Methods: Thirty-seven patients with congenital heart diseases were selected by echocardiography before transcatheter closure,in which there were 20 cases of secundum atrial septal defect (ASD),10 cases of ventricular septal defect (VSD),and 7 cases of patent ductus arteriosus (PDA),all of the patients underwent transcatheter closure using the Amplatzer occluder,the diameter occluder device is 2-4 mm wider than measure of echocardiography.The Amplatzer occluder closure procedure which monitored by X-ray and TTE was observed.TTE was performed 1 day,1 week,1 month and 6 months after operation,in order to measure the size of heart and to find whether there were shunts in atrial septum,ventricular septum,large arteries lever and whether the occluder was dropted.Results: The successful transcatheter closure of ASD,VSD and PDA were 19,10,7 cases respectively.One day after operation on TTE,there a slight shunt was detected in 1 case of ASD,a little regurgitation was remained in tricuspid valve of 1 VSD patient,two VSD patients developed a variety of heart block.No shunt was detected in all cases 1-6 months later.Conclusions: TTE has the great usefulness in choosing suitable patients,selecting the size of occluder,examining whether the location is suitable in operation and whether has the residual shunts after operation.It is also important for evaluation of curative effects.