A method and apparatus for transmitting control information in a wireless communication system is provided. The method includes transmitting common control information including a multiple input multiple output (MIMO) indicator indicating single user-MIMO (SU-MIMO) or multi user-MIMO (MU-MIMO) to a receiver, generating first precoded dedicated control information by performing precoding on dedicated control information including information for the MU-MIMO by the use of a first precoding matrix, generating second precoded dedicated control information by performing precoding on the first precoded dedicated control information by the use of a second precoding matrix and transmitting the second precoded dedicated control information to the receiver.