The article shows the scarce attention given by the mass sociology to the information production conditions in comparison to the study of mass media discourse. It declares, however, that both types of study should be interrelated and complementary, proposing as a model of investigation the fields theory. This has two advantages to the researcher: first, it allows to distinguish levels in the professional field analysis of journalism, and aecond, it recognizes the economic, political, discursive, prefessional and social conditions that determine the journalistic work.