Objective　To explore the clinical characteristics and cerebral MRI characteristics of mitochondrial encephalomyopathy with hyperlactic acidemia and stroke-like episodes (MELAS) syndrome and to improve the clinical doctors understanding of the specific manifestations of cerebral MRI in MELAS syndrome.Methods　The clinical features and cerebral MRI data of 17 patients with MELAS syndrome diagnosed by gene test or muscle pathology in our hospital from February 2011 to September 2020 were retrospectively analyzed.Results　Among the 17 patients with MELAS syndrome,there were 7 males and 10 females.Epilepsy（6/17） and headache（4/17） were the main initial symptoms,and the main clinical manifestations were headache,epilepsy and visual impairment.The main characteristic of cranial MRI is abnormal signal in cerebral hemispheric cortical region.And the lesions were mainly located in the temporal lobe,parietal lobe and occipital lobe.There were 3 cases of single lobe involvement,only 1 case of basal ganglia involvement,and 13 cases of multiple lobe involvement,and 6 patients had cerebral and/or cerebellar atrophy.Abnormal signals of injury included long T1 and long T2 signals at the lesion site,high signal in DWI and FLAIR sequence,and abnormal lactic acid peak (Lac peak) on MRS.Conclusion　The clinical manifestations of MELAS syndrome are complex.For patients with craniocerebral MRI indicating abnormal signals of temporal lobe,parietal lobe and occipital lobe with headache,epilepsy and other symptoms,the possibility of MELAS syndrome should be highly suspected.Further muscle pathological examination and gene detection are recommended.