A method for selecting a ferrite bead for a filter to avoid a peak value in a frequency response curve of the filter is provided. The method includes the steps of: building an equivalent model database including parameters of equivalent models of ferrite beads, the parameters including an inductance and a capacitance of a corresponding equivalent model of each ferrite bead; calculating parameters of a desired ferrite bead in the filter based on parameters of the filter, the parameters of the ferrite bead including an inductance, a capacitance, and a resonant frequency; adjusting parameters of the filter until the calculated resonant frequency equals or approaches a desired resonant frequency, and finding an inductance and a capacitance respectively equaling or approaching the calculated inductance and the calculated capacitance in the database; and selecting a ferrite bead with the appropriate inductance and capacitance as found in the database for the filter.