Provided is a method and an apparatus for transmitting a large quantity of control information in a mobile communication system. When there is no uplink data to be transmitted, a UE spreads second control information, a quantity of which is less than or equal to a pre-defined threshold, by using a ZC sequence cyclic-shifted according to resource blocks, each of which indicates at least one time interval used for a transmission of the second control information. When there is uplink data to be transmitted, the UE performs TDM of the uplink data with third control information. When there is no uplink data to be transmitted and the quantity of control information exceeds a pre-defined threshold, or when the first control information includes various types of information, the UE spreads the first control information in a time domain by the orthogonal codes.