In doing Auditory Brainstem Response(ABR), usually the click sound is used as stimulus sound. But as the click sound has no frequency specificity, there had been many attempts to use the tone burst as stimulus sound. It has been known that as the ABR is an on-response so the rising and fall time of the tone burst influences the wave form and latencies but the duration time has no effect on ABR. But recently, there was a report that the duration time of the tone burst has some effect on the latencies of ABR, so I observed the latencies of ABR by using tone burst in 20 normal hearing adults. The results were as follows : 1) When the on time was elongated and off time shortened, the latencies of the wave I, III, V, VI showed marked elongation, but he interwave latencies showed unremarkable change. 2) When the off time was sufficiently given as the on time elongated, the wave and interwave latencies of ABR showed unremarkable change.