This paper proposes noise-source parameter identification of the noise-source equivalent-circuit model for predicting conducted noise while considering the switching fluctuation of a DC/DC converter. We decomposed measured conducted noise into ripple noise, turn-on spike noise, and turn- off spike noise to prevent the accuracy degradation in the parameter identification. The predicted conducted noise spectra show the error with the measurement was within 3 dB up to 200 MHz, which is more accurate than that in our previous study.