Abstract: The issue that buffer resistance and imperfect characteristic impact on the impulse current measurment is studied. The circuitry is simulated with MATLAB software. The 8/20μs、1/20μs lightning waveforms are simulated by double exponential function. The impact on the impulse current measurment is observed by changing the values of the buffer resistance. The impact of resistance, inductance and the capacitor with imperfect characteristic on the measurment result of Rogowski coil is analyzed, and the impact on thick winding coils and thin winding coils are analyzed.It is concluded that the buffer resistance and the element with imperfect characteristic can greatly impact on the reality and responsivity of the head wave.It is suggested that while making a Rogowisk coil, the buffer resistance should be chosen according to time condition, and values of the parasitic inductance and capacitor of the element, and the winding method and material of coil should be considered.