Article is devoted consideration of some features to creation of "alternative" forms of a family and marriage, namely, to studying of such phenomenon as, co-habitation which conducts to loss of values of traditional forms of marriage, and also growth of process of illegitimate birth rate and other consequences. Now in a modern society "civil marriage" has got the certain legitimacy, with the given relations already to surprise nobody, and many justify its existence. In Russia "civil marriage" is a co-habitation of the people, doing not wish to connect itself the matrimonial both parental rights and the duties, therefore the traditional family gradually loses the appeal to a considerable part of the population. And the family based on alternative forms to marriage, namely, co-habitations, cannot is high-grade to carry out functions inherent in it. This modern phenomenon completely is not studied yet, and reserves weight of questions, and value for the most social institute of a family demands definition of its place, and. Article has the research character expressed in a teoretiko-methodological basis of research. As a material publications of domestic and foreign researchers in the periodicals acting, as a part of extensive mass media which form public opinion are used.