In the field of wireless communication, a method and an apparatus for transmitting Uplink Control Information (UCI) are provided. The method includes: determining a codeword corresponding to the UCI among multiple codewords according to a preset rule when the UCI is transmitted on a Physical Uplink Shared Channel (PUSCH) with the multiple codewords (101); and transmitting the UCI by mapping the UCI onto the corresponding codeword (102). The apparatus includes a determining unit and a transmitting unit. The method and the apparatus provide a solution to transmitting UCI on a PUSCH with multiple codewords. This solution can be implemented easily based on LTE R8, without involving too much additional work of standardization.