In this chapter, weCooperative bargaining will study two-person cooperative bargaining problem, in which two individuals (players) are faced with an uncountable number of alternatives and choose one of them using a pre-determined rule. A typical example for cooperative bargaining is the negotiation process between workers’ unions and organizations of employers about workplace issues and/or wages. The cooperative problem was theoretically formalized and studied first by [1]. The solution he proposed is a rule that maximizes the product of two individuals’ gains from bargaining. He showed that this bargaining rule, which we call the Nash rule, is the only bargaining rule that satisfies a certain set of axioms. In Sect. 16.1, we will present the cooperative bargaining problem and, in Sects. 16.2 and 16.3, we will present some well-known bargaining rules and some well-known axioms, respectively. Finally, in Sect. 16.4, we will provide characterization results for three well-known bargaining rules, including the Nash rule, the Kalai and Smorodinsky rule, and the Egalitarian rule.