Autism spectrum disorder (ASD) is significantly known as social interaction impairment that can be reduced through early school-age intervention. The quasi-experimental research design was used to examine the effect of applied behavior analysis treatment on ASD children's interpersonal skills. The researchers used a purposive sampling technique to select 30 participants who have symptoms of ASD, which were divided into two groups (control and experimental) without gender discrimination. The assessment of basic language and learning skills (ABLLS-R) protocol and portage guide of early education was used to develop a questionnaire comprising four factors. The results indicate a statistically significant difference between the experimental and control groups in terms of students' interpersonal skills and the pretest and post-test scores of the experimental group. It is suggested that parents and therapists should develop a sharing ability among children with autism symptoms so they can understand social reinforcement.