Based on psychological research and contemporary sociology of the family ,polygamy is a disorder in family structure. This tradition is linked to the ancient ages and primary human societies and in spite of the conflict and lack of compatibility with human nature , social relations and specific economic condition, political and cultutral due to the presense of such an intensity had been approved. In this article we have shown that this issue in ferdowsis shahnameh as one of the most important text left with avery rich and reliable sorce of social and cultural studies of poses is also to emerge. This tradition in the family structure, relationships such as the  stepfather,stepbrother ,stepmother,non-fraternity creates a tension and conflict among individuals contributes to impaired and the family is disfunctional . stepbrother deadly clashes in shshnameh appears to be a pattern repeated so that the shahnameh in any position that such relationships are formed , without exception land to the death of one of his halfbrother. In fact, this raticle will suggest that behavioral and mental health statuseof children  of polygamous families in shahnameh is not optimal or highlight itand traceit in shahnameh has proven this hypothesis