Method for resource allocation for downlink control channel in wireless communication system and apparatus therefor

A method in which a base station transmits a downlink control channel in a wireless communication system is disclosed in the present application. More specifically, the method comprising the steps of: within one resource block based on the number of available resource elements in the pair (pair), the size and the one of the resource blocks in resource allocation unit for a downlink control channel pair (pair) determining the number of resource allocation unit; And a step of mapping a downlink control channel for transmission resources in a resource block pairs, a predetermined number according to the determined resource allocation unit; And the downlink control channel includes the step of transmitting to the mobile station, and a size of the resource allocation unit is defined as the number of resource elements wherein the variable according to the number of the available resource elements.