Disclosed are a method and apparatus for transmitting a power control command. The method for a UE side thereof comprises: determining a TPC-RNTI corresponding to each carrier group and a tpc-index corresponding to each carrier group; detecting a PDCCH adopting a DCI format 3/3A and scrambled by using the TPC-RNTI corresponding to each carrier group in a common search space of a PCC; and according to the tpc-index corresponding to each carrier group, determining the position of an uplink power control command corresponding to the carrier group in the detected PDCCH scrambled by using the TPC-RNTI corresponding to the carrier group, and acquiring the uplink power control command corresponding to the carrier group from a corresponding position. Thus, a user equipment transmits a corresponding uplink power control command while supporting that uplink channels are transmitted over different uplink carriers corresponding to different carrier groups, thereby guaranteeing the normal and stable operation of a system.