Abstract:Objectives：To analyze the disease spectrum characteristics of 4，427 cases of children patients in pediatric intensive care unit in a certaingrade A tertiarychildren’s hospital，and to provide reference for clinical diagnosis and treatment，prevention and health care in critical patients. Methods：From 2019 to 2020，the basic information，clinical diagnosis and treatment information of hospitalized children in ICU were collected from electronic case system and medical record system. According to age，they were divided into sixgroups：neonatal period，infant period，toddlerperiod，preschoolperiod，school age and adolescence. The disease spectrum，hospitalization expenses and hospitalization days of different age groups were analyzed. Results：The proportion of male and female was 1.43∶1，and the non-medication hospital rate was 13.7 %，and the severe mortality rate was 1.5 %.The person times of hospitalization for respiratory disease in 2020 was significantly lower than that in 2019. There were significant differences in total hospitalization expenses，hospitalization days and gender distribution among different diseases（P < 0.001，P < 0.001，P=0.03）. The top three diseases were perinatal diseases，injury and poisoning，and respiratory diseases. The distribution of severe diseases in all age groups is scattered except infant. The top five causes of injury poisoning were traffic accidents，poisoning，falling accidents，falls/falls，burns/corrosion respectively. Overdose of drugs is the main cause of adolescent injury and poisoning. Conclusion：Prevention of accidental injuries among children and adolescents should be strengthened，and early identification of critical illness in children，innovated the management mode of intensive care，andrational planning of the use of severe medical resources.