An apparatus for controlling transmission power of a mobile communication terminal. The apparatus comprises a central processing unit for measuring a power level of a received signal and determining a power amplification mode in response to the measured power level of the received signal and a power preset table, a driver amplifier for amplifying a transmission signal to produce an output signal, the driver amplifier has operating conditions chosen in accordance with the power amplification mode, a voltage converter for outputting a preset voltage value in accordance with the power amplification mode, and a power amplifier for amplifying the output signal of the driver amplifier in response to the outputted preset voltage value.