The process of writing needs a complex coordination of cognitive, perceptual and motor skills. Handwriting is a part of the everyday life of a school child. Skills needed for writing, include the growth of the small muscles of the hand, eye-hand coordination, the ability to keep writing tools and graphic skills. These skills are prerequisite for perceptual motor skills. Perceptual motor skills have major role in learning process. So, in this study, the effect of perceptual motor interventions on perceptual motor function of drawing skills and dexterity is investigated in mentally retarded children. Inclusion criteria include Educable Down Syndrome children with conform diagnosis by clinical psychologist, without significant skeletal, neurological and mental illness and the age group is between 4.5 and 14.5 years. Exclusion criteria include non-cooperative child and Absence more than one session. In this study, using a simple non-probability sampling method and the sample size formula were considered 10 children in the treatment group and 10 children in the control group. Treatment group for 10 weeks, 3 sessions per week for one- hour exercises; motor perceptual and visual perception exercise are taught. Control group are received General education school. All the subjects will be tested. Then, they will be treated occupational therapy for ten weeks. After 10 weeks, all the subjects will be retested. After statistical analysis, the effectiveness of treatment on motor perceptual function will be investigated. This study is single blind.