Objective　To investigate clinical characteristics and treatment of acute myelitis in children. Methods　Clinical data and prognosis of two cases of pediatric acute myelitis with positive serum monosialoganglioside (GM1） antibodies were analyzed, and related literatures were reviewed. Results　Two cases had clinical symptoms and MRI change of myelitis with positive serum GM1-IgM antibody and thyroid antibody. Two cases had positive serum Helicobacter pylori IgG antibody and one case has positive Mycoplasma pneumoniae IgM antibody. After treated with high doses of glucocorticoid and gamma-globulin, two cases were discharged as symptoms improved. After discharged, treatment with oral prednisone and rehabilitation were continued. One case recovered completely while another could stand alone by supporting after 3 months follow-up. Conclusion　Immunologic injury played an important role in pathogenesis of acute pediatric myelitis with serum positive GM1 antibodies, which had better treatment outcome and prognosis. This type of myelitis may have intestinal Helicobacter pylori infection.