A spintronic wireless communication system for simultaneously modulating multiband frequencies and amplitudes includes a plurality of spin-torque transfer devices which have different frequency characteristics from each other, and OOK modulate or multi-level ASK modulate input data to thereby output a multiband OOK modulation signal or a multiband, multi-level ASK modulation signal; a plurality of matching networks which match individual impedances of the plurality of spin-torque transfer devices; and a broadband antenna which receives the multiband OOK modulation signal or the multiband, multi-level ASK modulation signal from ends of the plurality of matching networks and simultaneously transmits the signals to the outside.