There have been several results that illustrate the best performance that a network can get through cooperation of relay nodes. For practical purposes, not all nodes in the network should be involved at the same time in every transmission. Therefore, optimal partner selection protocols in cooperative wireless networks are believed to be the first important thing that should be paid attention to. This problem in our article is considered in the context of regenerative nodes and non-altruistic cooperation (no pure relay exists; all nodes have their own data to transmit). For each transmission, the protocol must provide the user (source node) a ‘best partner’ (relay node) to cooperate with (for network simplicity and less transmission signals here, assume that each user has only one cooperative node). A criterion is essentially needed when defining what a ‘best partner’ is; in this article, two factors, i.e,. the successful transmission probability and the transmission power, are considered. Three optimal partner selection strategies with different goals are proposed and analyzed respectively. The simulation results show that these are all supposed to be good tradeoffs between power consumption and transmission performance. There have been several results that illustrate the best performance that a network can get through cooperation of relay nodes. wireless networks are believed to be the first important thing that should be paid attention to. This problem in our article is considered in the context of regenerative nodes and non -altruistic cooperation (no pure relay exists; all nodes have their own data to transmit) For each transmission, the protocol must provide the user (source node) a ’best partner’ (relay node) to cooperate with (for network simplicity and less transmission signals here, assume that each user has only one cooperative node). A criterion is essentially needed when defining what a ’best partner’ is; in this article, two factors, ie, the successful transmission probability and the transmission power, are considered. Three optimal partner selection strategies with different goals are proposed and analyzed respectively. The simulation results show that these are all supposed to be good tradeoffs between power consumption and transmission performance.