Abstarct: Abstract Noise High power transmission lines or harmonic noise with constant frequency in the frequency range 50 to 60 Hz is one of the damaging factors in seismic data that reduces signal quality and signal-to-noise ratio. Failure to weaken this noise will have a negative effect on pre-transaction data processing and consequently on data interpretation. notch filtering is the most common way of attenuating this noise in seismic data. This method, while weakening the harmonic noise, negatively affects the signal frequency content of the harmonic noise frequency and its neighborhood. Hence, introducing a method that minimizes harmonic noise content while minimizing harmonic noise. Spectral interpolation method using simple interpolation algorithm interpolates the signal amplitude at the harmonic noise frequency with the help of signal frequency amplitude at neighboring frequencies. Evaluation results on synthetic and real data showed that spectral interpolation method is a good alternative to the split filter method.