Social capital is a classic concept which has been attracted attention of most researchers as its importance in modern political and social literature as well as central and deep role conceal in Its. Social capital has an intense affinity with totality of social system by means of a mediator variation. This mediator variation is function carried out by social capital. Indeed, social capital affects all the social sub-systems and influenced by them. However effects of this category on mentioned sub-systems have of higher search significance. In this article, it is attempted to be evaluate the most important political functions of social capital and finally this theoretic concept is investigated with regard to pathology the subject of likely dysfunctions on social capital.