Disclosed are a calibration method and a calibration circuit. The calibration method and the calibration circuit effectively calibrate the mismatches between the first signal path and the second signal path of a receiver by calibrating a plurality of tap coefficients of a finite impulse response filter configured in the second signal path and optimizing the tap coefficients. The calibration and optimization for the tap coefficients of the finite impulse response filter is according to differences between the electrical characteristics the analog-to-digital convertor and the LPF in the first signal path and differences between the analog-to-digital convertor and the LPF in the second signal path. These differences are obtained when the data reception has not yet started by the receiver (that is, when the receiver is working in a training mode).