摘要:According to the mother's key roles in bringing up emotional and cognitive abilities of mentally retarded children and respect to positive psychology in recent decades, this research is administered to assess the relation between mother's happiness level with cognitive- executive functions (i.e. attention, working memory, inhibition and planning) and facial emotional recognition ability as two factors in learning and adjustment skills in mentally retarded children with Down syndrome.This study was an applied research and data were analyzed by Pearson correlation procedure. Population is included all school children with Down syndrome (9-12 yr) that come from Tehran, Iran. Overall, 30 children were selected as an in access sample. After selection and agreement of parents, the Wechsler Intelligence Scale for Children-Revised (WISC-R) was performed to determine the student's IQ, and then mothers were invited to fill out the Oxford Happiness Inventory (OHI). Cognitive-executive functions were evaluated by tests as followed: Continues Performance Test (CPT), N-Back, Stroop test (day and night version) and Tower of London. Ekman emotion facial expression test was also accomplished for assessing facial emotional recognition in children with Down syndrome, individually.Mother's happiness level had a positive relation with cognitive-executive functions (attention, working memory, inhibition and planning) and facial emotional recognition in her children with Down syndrome, significantly.Parents' happiness (especially mothers) is a powerful predictor for cognitive and emotional abilities of their children.