The present invention relates to an apparatus and method for controlling uplink transmission power in a multiple element carrier wave system. The method for controlling uplink transmission power by a terminal in a multiple element carrier wave system includes the steps of: generating an uplink signal to be transmitted in a first serving cell; receiving, from a base station, random access start information for commanding the start of a random access procedure for a. second serving cell; calculating the estimated surplus power from first transmission power scheduled for an uplink signal transmission, and second transmission power scheduled for a transmission of a PRACH to which a random access preamble is mapped; and when the estimated surplus power is smaller than a threshold power, adjusting the first transmission power or the second transmission power on the basis of power allocation priority.