Objective To meet the demand of ECG signal processing in high sampling rate,a simple and narrowband power-line interference notch filter is designed.Methods Based on the band elimination filter which was combined with counteraction of zeros and poles and the interpolation theory,we designed a simple,integral coefficient filter with adjustable filter bandwidth.To eliminate the Gibbs phenomena,we adopted the average filter in linear segments which was designed by the former.Results With our designed filter,50 Hz power-line interference in high sampling rate was efficiently removed,and the filter coefficients were simple,integral,and convenient.Conclusion The new design can produce a narrowband notch filter in high sampling rate,remove the 50 Hz power-line interference effectively,and retain the significant signal as much as possible to meet the needs of ECG analysis.