The present invention relates to an apparatus for controlling power of mufti core processor, which includes a power control device by core unit, controls a plurality of power-related parameters by core unit, and thus decreases a load for power management and enables realization of a low power multi core processor through minute power control. The apparatus includes a processor core adapted to provide code information on an application program for executing to a power regulation controller, and a power regulation controller adapted to receive the code information on the application program from the processor core to determine an operation frequency of the processor core, set an operation voltage, a clock-gating value and a power-gating value according to the determined operation frequency, and provide the set values and voltage to the processor core.