The present invention relates to a wireless communication system. More particularly, the present invention relates to a method for transmitting control information through a PUCCH in a wireless system and to a device therefore, the method comprising the following steps: receiving a first modulation symbol and a second modulation symbol from the control information; diffusing in a frequency domain, the first modulation symbol to a plurality of subcarriers; diffusing in a time domain, the first modulation symbol diffused in the frequency domain to a plurality of contiguous first SC-FDMA symbols; diffusing in the frequency domain, the second modulation symbol to a plurality of subcarriers; diffusing in the time domain, the second modulation symbol diffused in the frequency domain to the plurality of contiguous first SC-FDMA symbols; and transmitting the diffused first modulation symbol and the second modulation symbol through the PUCCH.