The invention provides a method of selecting a base station according to which optimal quality can be achieved in the communication between a mobile station and a communication destination by efficiently using resources of the entire wireless network, as well as a mobile station and a base station. The base station selection method selects one from a plurality of base stations connected to the relay server, for a connection with the mobile station. In the method, each base station retains abase station routing cost which is a cost for the path connecting the base station to the communication network. And the mobile station measures a toward-base station routing cost for the path between itself and each base station, calculates a total routing cost for each base station by adding the base station routing cost and the toward-base station routing cost, and selects a base station associated with a minimal total routing cost when establishing a relay connection with the communication network.