In a few fragments of the Simmel´s work we can discover a sociology of the market which contemplate the rationalisation of social structure and the space of social interaction. With this aim, we begin our article relating the division of labour with the social networks and the innovation; in the next step we focuses our interest in the process of rationalisation, indicating its influence in the nature of market; finally, from Simmel´s essays and articulating divers social forms, we can contemplate the market as a space of social relations. These social forms are: interchange, competence, trust and bargaining.En diversos fragmentos de la obra de Simmel se esconden los fundamentos de una sociología del mercado que considera los procesos de ra...