Background & Objectives: Autism Spectrum Disorder (ASD) is a neural– evolutionary SYNDROME, i. e., among the most significant disorders in childhood. In other words, autism indicates an evolutionary disability which affects verbal and non– verbal communication, as well as social interactions. Moreover, this disorder usually manifests before the age of three years, and has undesirable effects on educational functioning. Playing music is a multi– sensory process which involves motor planning, preparation, and execution systems in individuals. Purposeful musical– motor activities make children with ASD to shift focus from their inner world to their surrounding environment; subsequently, they create a mutual relationship with the community and social acceptance in children with ASD. The present study aimed to investigate the effects of musical– motor activities on autism symptoms in children with High– Functioning Autism (HFA) disorder. Methods: This was a quasi– experimental study with a pretest– posttest and a control group design. In total, 22 children with HFA disorder and the mean± SD age of 8. 5± 1. 5 years and the mean± SD IQ score of 89. 36± 2. 31 were selected as study participants. Moreover, they were randomly divided into three groups, as follows: exercise intervention with music (7 children, 5 boys and 2 girls), exercise intervention without music (7 children, 6 boys and 1 girl), and the control group, including music (8 children, 6 boys and 2 girls). The study participants in the exercise intervention with music and non– music groups, practiced in a 12– week program of three sessions per week; each session lasted from 45 to 60 minutes. The Orff music was used in this study ) guitar, tombak, xylophone, Flute, drum, metallophone, improvisation, singing, blows with the body, nursery rhymes and consistent with music therapist(. The exercise intervention program included 5 to10 minutes of warm– up )walking, hand and foot stretching, & reviewing the learned movements), 35 to 45 minutes of main practice, that included 20 to 25 minutes of gymnastic fundamental movements (walking, jumping, static and dynamic balance, rabbit, flamingo, cat, crabs, dog, cow, kangaroo, hopping, bridge on shoulders, push– up, & movement on trampoline(, 10 minutes of practice with ball (catching, throwing & dribble), and 10 minutes of rhythmic movements (hands and feet creative and rhythmic movements). additionally 5 to 7 minutes was considered for cool– down, including stretching movements and relaxation. Moreover, the Garss– 2 Measurement Scale (Gilliam) was used for collecting data concerning autism symptoms in children with HFA disorder. The obtained data were analyzed in SPSS. Furthermore, we implemented Levene's test, Analysis of Covariance (ANCOVA), Analysis of Variance (ANOVA), and Bonferoni test at a significance level of 0. 05 for data analysis. Results: Results indicated that two groups of exercise intervention with music and without music performed better in stereotyped behavior, communication skills, and social interactions, compared to the control group. Besides, there was a significant difference between the two experimental groups in terms of stereotyped behavior (p<0. 001), communication skills (p<0. 001), and social interactions (p<0. 001). Conclusion: According to the current research findings, musical– motor activities were effective in the control and improvement of stereotyped behavior, communication difficulties, and social interactions in children with HFA disorder; these progresses were achieved through providing sensory feedback and replacing similar mechanisms. Rhythmic games, as well as rhythmic and creative movements lead to the control and improvement of stereotyped behavior, social interactions, and communication skills in musical– motor activities. Therefore, musical– motor interventions could be used to control and reduce the symptoms of autism and should be considered in designing training programs for this population.