In the study of auditory evoked-potentials (AEPs) under high stimulus rate paradigm, the generation of appropriate stimulus sequences in an automatic way will facilitate the research and application of such paradigm. This paper presents a method to obtain the applicable stimulus-sequence using a modified differential evolution (DE) algorithm. By defining an objective function in terms of jitter ratio (JR) and underlying constraint condition derived from the spectrum of the sequence, the method is able to gradually reduce the searching-space guaranteed by a dynamic scaling factor in the mutation process of the DE algorithm. Four compatible sequences are given to make comparisons with the manual selected sequences as reported. The performance evaluated by the synthetic data justifies the feasibility of the present method.