In this paper, an effective technique for circuit and waveform parameter extraction in an impulse current generation circuit is presented. The technique is derived from the integral form of an ordinary differential equation of which the solution corresponds to the functions of impulse current waveforms. Using an impulse current waveform collected from the experiment, the numerical integration and linear least-square approaches are also employed to determine circuit and waveform parameters. To verify the validity of the proposed technique, the proposed method has been utilized in some applications for waveform parameter evaluation and determination of the appropriate circuit parameters in the impulse current tests. Using the corrected parameters by the proposed method, the impulse current waveforms were precisely generated according to the standard requirement. The simulated results agree well with the experimental results. It is confirmed that the method is fairly highly accurate and very effective in computation cost due to no iteration requirement in the process of the parameter extraction. The technique is very useful in impulse current tests and helps test engineers select appropriate circuit components without trial-and-error approaches.Index Terms-Circuit parameter extraction, impulse current test, linear least square, numerical integration, ordinary differential equation (ODE).