Abstract: Objective To explore the clinical characteristics of posterior reversible encephalopathy syndrome (PRES) during chemotherapy in children with acute lymphocytic leukemia (ALL),and improve the understanding of the disease. Methods A retrospective analysis was performed on clinical data about 14 children with a definite diagnosis of ALL and PRES in the First Medical Center of Chinese PLA General Hospital from November 2008 to January 2019. Results Of the 14 cases,there were 5 males and 9 females,with a median age of 6 (2-13) years.Twelve cases developed PRES during remission of induction chemotherapy,and the median time from chemotherapy to onset was 16 (4-28) days.Except for typical symptoms,the clinical manifestations of PRES were abdominal pain and autism.MRI showed that the lesions were symmetrically distributed in the parietal-occipital lobes and portion cortical,presenting as hyperintensity on T1WI,T2WI and DWI sequences.Typical EEG features were visible slow waves in the background,and epilepsy-like discharges were occasionally seen.After treatment,12 patients achieved complete remission,and the median duration from symptom onset to cure was 15 (4-26) day;one patient developed irreversible visual impairment,one patient died before achieving complete remission,and one patient relapsed during sequential chemotherapy.According to the early warning scoring of PRES,cases were divided into electroencephalogram (EEG) low-risk group (6 cases) and EEG high-risk group (8 cases).In the EEG high-risk group,the duration of symptoms was positively correlated with EEG score with a correlation coefficient of 0.864 (P=0.001). Conclusion PRES frequently occurs during remission of induction chemotherapy,and its clinical features are abdominal pain and autism.The EEG can assist early clinical diagnosis and has certain clinical significance for predicting the prognosis of children.