A method and a user equipment for transmitting control information in a communication system are discussed. The method according to an embodiment includes multiplying a transmission information symbol s for the control information by a frequency direction sequence c(k) to generate a first output sequence s(k), where s(k)=s*c(k), k=0, . . . , Nk−1, and Nk corresponds to a number of subcarriers included in a resource block allocated for an uplink control channel; multiplying the first output sequence s(k) by a time direction sequence x(n) to generate a second output sequence s(k, n), where s(k, n)=s(k)*x(n), n=0, . . . , Nn−1, and Nn corresponds to a number of symbols used for transmission of the control information in a transmission time interval; and transmitting the second output sequence s(k, n) through the uplink control channel in the transmission time interval.