Mission archéologique de Mad a)in S@ alih@ (Arabie Saoudite) : Recherches menées de 2001 à 2003 dans l'ancienne H@ ijr a des Nabatéens (1) Hégra, H@ ijr a, al-H@ ijr, Mad a)in S@ alih@ , quatre noms différents pour désigner l'un des sites archéologiques majeurs d'Arabie Saoudite et le site nabatéen le plus important après la capitale du royaume, Pétra, en Jordanie. Cela est dû non seulement à la quantité de vestiges qui y ont été découverts mais également aux informations qu'il est à même de livrer, notamment -mais pas seulement, nous le verrons -du fait de la présence d'un ensemble épigraphique nabatéen sans équivalent ailleurs. C'est enfin le site nabatéen le plus méridional de la Nabatène.Le site appartient au domaine géographique de l'Arabie du Nord-Ouest (Fig. 1). Il se trouve à environ 400 km au nord-ouest de Médine et à This contribution presents the preliminary results of the Mad a)in S@ alih@ archaeological project, which started in 2001 and which, in December 2004, completed its fourth field season. The aims of this five-year project are a systematic recording of the archaeological remains at the site as well as an analysis of its agricultural potential. The former include not only the tombs, sanctuaries, wells, quarries, walls, buildings, etc., but also the inscriptions written in various scripts and languages. Parallel to this exploration of what is visible on the surface, an extensive geophysical survey was undertaken in the so-called residential area, in the central part of the site, in order to obtain an image of the sub-surface remains. This contribution begins with a presentation of the sources, followed by a brief history of the exploration of Mad a)in S@ alih@ . The focus is on the conditions which allowed this project to be established as well as the problematics which guided it. J.-B. Rigot then presents his analysis of the agricultural potential of the site, demonstrating the existence, in antiquity, of a large oasis. Finally, a preliminary description of the main components of the sites: the necropoleis, the sanctuaries and the residential area, is given.