Objectives This study was conducted to design Individual Differences intervention based on parents' expressed emotion and its impact on children's social skills with high-functioning autism disorder. Methods The first part of this study is comparative-causal and the second part is a semi-experimental study. In order to design Floortime treatment plan based on parents' expressed emotion, first in an Embedded Design Mixed Research Method by means of researcher's questionnaire for qualitative measurement and family questionnaire for quantitative part of emotional state of mothers with autistic children were measured. Accordingly, the treatment plan with 23 meetings was codified. Finally, 20 children with high-functioning autism were selected from the autism centers by available sampling. Out of them, 10 children were put into the experimental group and they were provided designed intervention plan in addition to the ABA intervention, and the other 10 children formed the control group, who merely received Applied Behavior Analysis (ABA) intervention. Tools used were Family Questionnaire, ASSQ test, Stanford-Binet intelligence test, and Gilliam and Vineland social compatibility tests. Results Results show that there are significant differences in mother's expressed emotion in case of normal and autistic children. The expressed emotion of mothers of autistic children is high in terms of the total score of expressed emotion, criticism, and Emotional Over-Involvement (EOI). After the intervention, no significant difference was observed in the social compatibility and communication skills between the two groups of children who were under the ABA intervention and who were under Floortime intervention. But after the intervention, the experimental group had a better score in relation variable. Conclusion Given the high level of excitement expressed by parents of children with autism, various interventions have to reduce their excitement. You can also use social interventions such as floortime intervention to increase the association of children with high performance autism disorder.