Purpose: The present study investigated the age of diagnosis, treatment and demographic factors of Chinese children with autism spectrum disorders (ASD), to provide a scientific basis for the early detection, diagnosis, and intervention of ASD. Patients and Methods: A total of 1500 ASD children aged 2-7 years old from 13 cities in China were administered questionnaires to examine their diagnosis, treatment, and basic family information. The Childhood Autism Rating Scale (CARS) was used to measure the symptoms and severity of ASD children, and the Children Neuropsychological and Behavior Scale-Revision 2016 (CNBS-R2016) was utilized to measure neurodevelopmental levels of ASD children. Results: We found that for children with ASD, the median (p25, p75) age for the initial detection of social behavioral developmental delay was 24 (18, 30) months, while the age for the initial diagnosis was 29 (24, 36) months and the age for the beginning of intervention was 33 (27, 42) months. Multiple linear regression (MLR) analysis suggested that in children with ASD whose parents were divorced, separated, or widowed, or whose mothers were engaged in physical work, the initial detection of social behavioral developmental delay happened later. For the children with ASD who lived in urban areas, had higher levels of ASD symptom severity or whose parents were not divorced or separated, the age for the initial diagnosis was earlier. For the children with ASD who lived in urban areas or whose mothers had received higher level of education, the earlier age for the beginning of intervention was observed, while for those with ASD whose mothers were engaged in physical work, the age for the beginning of training was later. Conclusion: It is recommended to actively carry out health education of ASD and strengthen the support for ASD families to enhance their rehabilitation level.