Purpose: This study examined the efficacy of parent training interventions to facilitate social reciprocity and language development in children with autism. Methods: The social interaction behaviors of mothers and children over time were compared using single subject design experimentation methodology. five children who were diagnosed with autism and their mothers participated in the study. The participants were recruited from U city, Korea. The mothers were trained using training videotapes and demonstrations on how to facilitate social interaction with their children as well as promoting language development. following the training, data were collected three times per week by video taping mother-child interaction in their homes. Results: Four of the five mothers demonstrated increases in the use of imitation with animation and expectant waiting after the intervention compared to the baseline sessions; the children demonstrated noticeable increases in the use of initiation of interaction, vocalizations, and verbal production after their mothers received the training intervention. Conclusion : Results of this study demonstrate the efficacy of mother training to improve social interactions of children with autism. Additional important information can be gained by replicating this study with more participants and comparing intervention and control groups. Clearly, this intervention shows promise and has implications far clinical practice.