Résumé : Although the lexicometry bases itself on a classic way of scientific reasoning (contextualisation of the data, round trips between data, outcome and hypotheses), it is again little used in political sciences in the analysis of the political discourses. To assure better its dissemination, this article returns on its main tools and the scientific predicates of this method. It illustrates then its heuristic strength by showing through examples of analysis of two corpuses of texts produced by the European Union the interest of a reading forced by the focus on the lexicon seen as 'networks of words'. Specifically when texts seem to be 'neutral'. © 2009, equinox publishing.