Generally, ethnologists deal with kinship, while sociologists are mainly concerned by family. In this article, Jean-Hugues Déchaux, highlight the interest of a sociology of kindship. With the help of statistical data, he carefuly examines the means and functions by which economical patrimony is transmitted. He also underlines the role of kindship facing unemployment, childcare (itself linked to female work) or different reciprocal services between ancestors and descendants that kindship plays a decisive role in the process of social reproduction.Les relations de parenté occupent d'ordinaire les ethnologues, tandis que les sociologues s'intéressent plutôt à la famille. Jean-Hugues Déehaux, dans cet article, montre tout l'intérêt d'une sociol...