A method is provided for transmitting uplink control information by a terminal in a cellular communication system. The method includes receiving system information associated with uplink transmission of a Sounding Reference Signal (SRS) from a base station; determining an orthogonal sequence having a first length or a second length predefined; transmitting uplink control information to which a first orthogonal sequence is applied, if the first orthogonal sequence having the first length is determined; and transmitting uplink control information to which a second orthogonal sequence is applied, if the second orthogonal sequence having the second length is determined. The SRS is selectively transmitted with the uplink control information, based on the received system information, and the uplink control information, to which the first orthogonal sequence having the first length is applied, is transmitted regardless of whether or not the SRS is transmitted in a corresponding slot.