Abstract: Objective To explore underlying causes of presumptive optic neuritis(ON)in children.Methods Retrospective study of continuous cases with presumed diagnosis of optic neuritis in childhood.Results 104 cases(65.8%)met ON criteria in this cohort of children,among which 80 cases(76.9%)were considered as idiopathic demyelinating optic neuritis(IDON).Infectious optic neuritis and inflammatory optic neuropathy were found on 3 cases respectively.The cause of 18 cases remains unknown.Leber hereditary optic neuropathy and non-organic visual acuity loss account most of the 54cases misdiagnosed as optic neuritis.Conclusions As in adult patients,idiopathic demyelinating optic neuritis is the most common pathogeny of optic neuritis in children,while infectious events were more common in children.Leber hereditary optic neuropathy and non-organic visual acuity loss were the most common disease confused with optic neuritis in childhood.Some rare disease in childhood which can causeoptic nerve lesion should also be considered.