A transmitter with compensating mechanism of pulling effect includes an output unit and a correction unit. The output unit mixes a first correction signal and a second correction signal according to an oscillating signal to generate a modulated signal, and to amplify the modulated signal to generate a first output signal. The correction unit analyzes the power of the first output signal to generate a first coefficient and a second coefficient, and generate the first correction signal and the second correction signal according to the first coefficient, the second coefficient, an in-phase data signal, and a quadrature data signal.