Abstract: Objective To study the intraoperative care for patients with perimembranous ventricular septal defect（mVSD） during its closure. Methods Thirty-eight patients with mVSD（21 males and 17 females） at the age of 3-53（15±9.2）years diagnosed according to their clinical examination,echocardiography and left ventricular angiography were enrolled in this study.Closure procedure was performed for their mVSD under the guidance of X-ray and echocardiography.The patients were closely monitored by intraoperative ECG.Different rescue drugs,equipments and special catheters were prepared to prevent the recurrence of complications. Results The closure rate for mVSD was 100% and no complication occurred during the procedure. Conclusion The closure procedure for mVSD is safe and effective.Intraoperative psychological care for patients,skilled collaboration and intensive monitoring are the keys to the success of closure procedure for mVSD.