The work presented in this paper aims at developing a Personalized Information Retrieval system in Arabic Texts (“PIRAT”) based on the user's preferences/interests. For this reason, we proposed a user’s modeling and a personalized matching method document-query. The proposed user’s modeling is based on a hybrid representation of the user profile. In this approach, we introduce an algorithm which automatically builds a hierarchical user profile that represents his implicit personal interests and domain. It is to represent the interests and the domain with a conceptual network of nodes linked together through relationships respecting the linking topology defined in the domain of hierarchies and ontologies (hyperonymy, hyponymy, and synonymy). Then, we address the problem of unavailable language resources by building i) a large Arabic text corpus entitled “WCAT” (ie 30550 articles) and ii) i) Building our own Arabic queries corpus entitled “AQC2” in order to evaluate the suggested PIRAT system and AXON system. The results of this evaluation are promising.