A polar receiver using injection-locking technique includes an antenna, a first filter, a first voltage-controlled oscillator, a first mixer, a frequency discriminator, a second filter, a third filter, a first analog-digital converter, a second analog-digital converter and a digital signal processing unit. Mentioned polar receiver enables to separate an envelope signal and a frequency-modulated signal from a radio frequency signal received from the antenna via the injection locking technique of the first voltage-controlled oscillator and the frequency discriminator. The envelope component and the frequency-modulated component can be digitally processed by the digital signal processing unit to accomplish polar demodulation.