The present invention relates to the construction of output stage of the Doherty amplifier and comprises a main amplifying unit, an auxiliary amplifying unit and a compact λ/4 line connecting two amplifying units. The compact λ/4 line connecting two amplifying units includes a first parallel capacitor grounded by being connected to the main amplifying unit in parallel; a second parallel capacitor grounded by being connected to the auxiliary amplifying unit in parallel; and an inductor or a microstrip transmission line connecting the main amplifying unit and the auxiliary amplifying unit. The Doherty amplifier in accordance with the present invention further comprises a matching network unit connecting to a final output by connecting the main amplifying unit and the auxiliary amplifying unit and; and a λ/4 line used as the voltage inputs of the main amplifying unit and the auxiliary amplifying unit.