An apparatus and method are provided for transmitting data and control information in a wireless communication system. The method include determining if the control information is to be transmitted via a data channel; and if the control information is to be transmitted in the data channel, determining a number of symbols for coded control information in consideration of the data, generating the coded control information based on the number of symbols for the coded control information, generating coded data based on an MCS for the data, multiplexing the coded data and the coded control information, modulating the multiplexed coded control information and coded data by a modulation scheme, performing FT on the modulated coded control information and coded data, performing IFT on the FTed coded control information and coded data based on sub-carrier mapping, and transmitting the IFTed coded control information and coded data via the data channel.