The invention provides a wireless transmission apparatus, a phase compensating apparatus, and a phase compensating method thereof. The phase compensating apparatus includes main transmission wire, a plurality of capacitors, and at least one phase compensating unit. The main transmission wire is coupled between the output end of the power amplifier and the input end of the impedance matching apparatus. A first end of each of the capacitors is coupled to the main transmission wire. The phase compensating unit has two ends for being coupled to second ends of two of the capacitors.