Objective: To evaluate the effect of enzyme replacement therapy (ERT) on glycogen storage disease typeⅡ(GSDⅡ). Method: The clinical data of three juvenile onset and two infant onset GSDⅡpatients were collected from First Affiliated Hospital of Sun Yat-sen University in October 2015 to July 2016.Patient 1 was female, the age of onset was 15 months. Patient 2 was male, the age of onset was 20 months. Patient 3 was female, the sister of patient 2, the age of onset was 47 months. Patient 4 was male, the age of onset was 5 months. Patient 5 was male, the age of onset was 1 month.The age at the start of ERT of the 5 patients was 32, 31, 56, 34, and 3 months respectively and the duration of ERT was 19, 9, 4, 5, 5 doses respectively.ERT was administered at 20 mg/kg every 2 weeks.Dexamethasone was regularly given before each infusion. Result: ERT was well tolerated, only one time, Patient 1 developed tachycardia and hypertension without using dexamethasone.Patient 2 underwent successfully ventilator weaning.Patient 1 underwent a tracheotomy, also needed mechanical ventilation treatment.Patient 4 noninvasive ventilation was tried. Conclusion: Recombinant human alpha-glucosidase treatment was effective and well tolerated in patients with GSDⅡ.