报告三例儿童ＭＥＬＡＳ综合症。其中男２例，女１例，年龄９～１４岁。临床症状以抽搐为主的癫痫样发作和卒中样发作、肢体瘫痪、轻偏瘫、缓解和反复发作、逐渐智力减退。头颅ＭＲＩ示额、顶、枕、颞叶和双侧基底节区多发性长Ｔ１和长Ｔ２异常信号，呈灶状、囊状和层性改变。２例肌活检可见ＲＲＦ和异常线粒体。诊断符和ＭＥＬＡＳ型。本文对临床症状、实验室检查、脑电图、影像学所见及治疗等进行讨论 Three cases of children reported MELAS syndrome. Including 2 males and 1 females, aged 9 to 14 years old. Clinical symptoms of convulsions-based epileptic seizures and stroke-like episodes, limb paralysis, hemiparesis, mitigation and recurrent, and gradually mental decline. Head MRI showed the abnormalities of multiple long T1 and long T2 abnormal signals in the apical, occipital, temporal lobe and bilateral basal ganglia, with focal, cystic and cystic changes. 2 cases of muscle biopsy showed RRF and abnormal mitochondria. Diagnostic character and MELAS type. This article discusses clinical symptoms, laboratory tests, electroencephalography, imaging findings, and treatment