A method for predicting and debugging electromagnetic interference (EMI) characteristics of an integrated circuit (IC) system includes the following steps: selecting a frequency domain range according to transformed raw data of the IC system to generate a blocking frequency analysis result, wherein the transformed raw data are transformed by a time-frequency waveform transformation; setting criteria data; comparing the blocking frequency analysis result with the criteria data to generate at least one comparison result; and generating a pass analysis report when a processing unit determines that each comparison result is passed; otherwise, executing an EMI design time-frequency analysis.