Abstract : Cognitive radio (CR) can be presented as a new paradigm coming from the bad use of spectrum resources, the problem of static spectrum allocation produce disequilibrium. The CR proposes opportunist radio spectrum exploitation. In this paper, we propose a centralized dynamic spectrum access in cognitive radio networks based on a powerful mathematical tool, the game theory on one side, and on multi-agent system on the other side. The problem of dynamic spectrum access (DSA) is modeled as a cooperative and non-cooperative spectrum access game where secondary users (SUs) access simultaneously multiple spectrum bands left available by primary users (PUs). Cooperation is modeled between PUs where non-cooperation is considered between SUs.