A method and system for resource allocation is provided. A method includes identifying a set of resource blocks associated with a control channel for a terminal; transmitting, to the terminal, information on the set of resource blocks on a radio resource control signal, the information including first information indicating resource blocks included in the set of resource blocks and second information indicating a number of symbols corresponding to the set of resource blocks; transmitting, to the terminal, control information including information for downlink data on the control channel identified based on the first information and the second information; and transmitting, to the terminal, the downlink data on a data channel based on the control information. The set of resource blocks includes at least one control channel resource. A search space for the control channel of the terminal is defined based on an aggregation level, a number of the at least one control channel resource, and a number of a candidate associated with the control channel.