A method for transmitting a control signal to a relay node at a base station in a multi-input multi-output (MIMO) wireless communication system is disclosed. The method comprises configuring relay-resource element groups (R-REGs) in a unit of four resource elements (REs) contiguous in the ascending order of subcarrier indexes, except for resource elements for a reference signal (RS); allocating transmission resources to the control signal in a unit of the relay-resource element group; and transmitting the control signal to the relay node by using the allocated transmission resources, wherein the resource elements for the reference signal include resource elements for channel state information-RS (CSI-RS), which include resource elements for a channel state information RS to which a transmission power of 0 is allocated.