Abstract To detect and alleviate harmonic resonance in a power system have been a delicate issue. In this paper, the effect of load modeling on resonance behavior of power systems employing eigenvalue sensitivity analysis is investigated. The most influencing parameters to mitigate resonance modes are detected using the sensitivity of critical eigenvalues with respect to the network various components in a frequency range. Also, results inferred from the criteria of driving point impedance and bus participation factors are compared with those of the sensitivity analysis with different load models. Where to locate capacitors and filters to mitigate the resonance modes is obtained using these criteria. The methods are tested on the well-known New Zealand as well as IEEE-30 bus test systems. Simulation results are discussed in detail to investigate the methods’ efficiency and capability.