A method of a power increase/decrease request of a user equipment in a wireless communication system using a plurality of frequencies is disclosed. The method of operating of a user equipment comprises receiving grants for each of the plurality of uplink frequencies from a base station; dividing a maximum power of the user equipment for each of the plurality of uplink frequencies in accordance with the received grants, and selecting a corresponding transport block for each of the plurality of uplink frequencies by considering the received grants; and comparing a remaining power of the user equipment to a power obtained by subtracting a power required to transmit a first transport block selected for a first uplink frequency from a power required to transmit a minimum transport block, which transmits more data than those of the first transport block.