User-contributed wireless networks are formed by wireless devices that are owned by different users. They have been widely used to achieve better connectivity at places where an infrastructure is not immediately available or cannot be directly used. The functioning of the user-contributed wireless network depends on the cooperation of the nodes in the network. In civilian wireless networks, nodes often belong to different users who have their own interests and always want to maximize their benefits. Consequently, the user nodes may not want to behave cooperatively, if it does not suit their needs and interests. Like many distributed autonomous systems, user-contributed wireless networks have the common incentive problems such as the free-rider problem, where only a small portion of user nodes contribute their resources, and the adverse selection problem, where user nodes do not reveal their states truthfully. So, to ensure the functioning of user-contributed wireless networks, it is highly important to provide incentives for nodes to cooperate. Game theory is a nature tool to deal with the problem of selfish behavior. In our work, we adopt solution concepts from game theory to study important incentive problems in user-contributed wireless networks. We mainly focus on two categories of incentive problems: routing problems and spectrum sharing problems. For routing, we have done four works. First, we considered the traditional deterministic routing in user-contributed wireless ad hoc networks, and proposed a mechanism to prevent the user nodes from colluding. Second, we studied the incentive issues for opportunistic routing in user-contributed wireless mesh networks, and proposed mechanisms to stimulate nodes to truthfully reveal their link states, so that the most efficient routing decision can be reached. Third, we proposed the first bargaining-based incentive mechanism for probabilistic routing that stimulates selfish nodes to participate in message forwarding. Fourth, we proposed a strategy-proof mechanism to efficiently distribute data flows among node-disjoint paths obtained by multipath routing protocols. For spectrum sharing, we studied multi-radio multi-channel assignment problem in a single collision domain, and proposed an incentive mechanism to ensure the system converge to equilibrium, named strongly dominant strategy equilibrium. At the same time, this equilibrium state achieves optimal system throughput.