As ideological matrix of the Saudi state and political and religious tool, the Hanbalo-wahhabi doctrine and its guardians, the ul?mm', are a double-edged sword that the political authority wants to control at all costs. Since 1970's, the monarchy aims at bureaucratizing this religious elite in order to supervise its access and to contain its opinions. In this context, several instances are created: the Committee of Senior Ulama, the Ministry of Justice, the Supreme Judicial Council, etc. Successive Saudi kings attempt measures of reform and modernization in legislation, in standardization of "law" and in the administration of justice. The objective of this attempt is to "unify" and monopolize the authority around a central pole which would break the balance of the Saudi sociopolitical structure. But many of these have been ad hoc measures, some qualified, reversed or made redundant by uldmn' opposition. The present paper, based on a fieldwork, analyses to what extent the legal system is autonomous in Saudi Arabia. This will allow us to gauge how the ulume' maintain a certain hold over this domain. The analysis will focus on three points: the complementarity, the cooperation and the competition between the political power and the ullmp' about legal questions.