Disclosed is an apparatus and a method for multiport amplification configured to amplify a signal input to a multi-input port and output the amplified signal to a multi-output port in order to normally transmit/receive a signal in a communication system. The apparatus and the method are configured to: amplify an input signal input through a multi-input port, detect a phase error and an amplitude error of the input signal, and then calculate a phase error value and an amplitude error value of the input signal; correct the phase error and the amplitude error of the input signal through the phase error value and the amplitude error value of the input signal; and then amplify the input signal of which the phase error and the amplitude error are corrected, and output the input signal to a multi-output port.