An apparatus and a method for reducing power consumption in a wireless communication system are provided. The apparatus includes an antenna, a Radio Frequency (RF) module, a first amplifier, an external power amplifier, and a controller. The RF module converts a baseband transmission signal to an RF signal. The first amplifier amplifies power of the RF signal inside the RF module. The external power amplifier amplifies power of an output signal of the first amplifier. When a transmission power level of a transmission signal is equal to or less than a maximum output level of the first amplifier, the controller controls to transmit the transmission signal amplified by the first amplifier via the antenna. When the transmission power level of the transmission signal is equal to or greater than the maximum output level of the first amplifier, the controller controls to transmit a transmission signal amplified by the external power amplifier via the antenna.