Objective To analyze the unplanned readmission status of 3-17 years old autistic inpatients in Beijing,and explore the influencing factors,so as to provide reference for improving the medical quality of mental diseases.Methods Data of hospitalized patients with autism aged 3-17 years from January 1 to December 31,2022 were collect-ed from municipal hospitals in Beijing,and the situation of 31-day unplanned readmission and intra-year unplanned re-admission was analyzed.Univariate analysis and Logistic regression analysis were used to explore the influencing factors of unplanned readmission.Results A total of 341 patients with autism were included.The 31-day and intra-year unplanned readmission rates were 7.0%and 18.8%,respectively.Age was the influencing factor of 31-day unplanned readmission for autism patients aged 3-17 years,and the length of first hospital stay was the influencing factor of 31-day unplanned readmission and intra-year unplanned readmission.Conclusion The unplanned readmission rate of children and adolescents with autism was low,the 31-day unplanned readmission rate of young children was relatively high,and the unplanned readmission rate of patients with a longer first hospitalization was higher.Measures should be explored to reduce the unplanned readmission rate of autistic patients and improve the quality of medical services for au-tistic patients.