A method for transmitting control messages is disclosed. The method includes grouping a plurality of control messages for at least one user equipment based on at least one criteria of whether or not uplink ACK/NACK channel indexes are allowed to be implicitly used in the control messages, whether or not the user equipment corresponding to the control messages is able to implicitly use the uplink ACK/NACK channel indexes, sizes of Information Elements (IEs) of the control messages, whether or not the control messages are segmented into a predetermined number of subblocks, MCS levels applied to the control messages, sizes of allocated IEs of the control messages after applying the MCS levels, and frequency partitions in which the IEs of the control messages are present, and transmitting the grouped control messages. The control messages included in each of the groups generated by grouping are equal in at said least one criteria.