Objective To investigate the prevalence of autism spectrum disorders (ASD) of children aged 4-6 years in public kindergartens in Shanghai.Methods Songjiang district and Xuhui district were selected randomly as the representative sample.By means of "Clancy Autism Behavior Scale","Social Communication Questionnaire" and "high-functioning Autism Spectrum Screening Questionnaire",all of the 33 public kindergartens in chosen area,which contained 10 385 children aged 4-6 years,were surveyed.Those who were screened as suspected cases would be further diagnosed by "Autism Diagnostic Interview-Revised" and "Diagnostic and Statistical Manual of Mental Disorders,Fifth Edition".Results Among 9 665 valid questionnaires,9 children were diagnosed with ASD.The ratio of male to female was 8:1,the point prevalence rate was 0.93‰.The results of ADI-R corresponded with that of DSM-5.There were two children who never had medical records.For others,"language" problem was the most likely reason for their parents to seek medical help,while "deficits in social communication" was the main symptom of patients.Conclusion The prevalence of ASD was lower than those recorded in literature,home and abroad which might be related to some patients not going to public kindergartens.