The acoustic startle response (ASR) is a useful neurophysiological measurement in translational research. People with ASD is known to have enhanced auditory perception, however, ASR to weak stimuli in ASD is not investigated well. Thus, the basic profile of ASR, including response to weaker stimuli, might be atypical in ASD, and, close examination of the profile is necessary in order to evaluate ASR. Here, we investigated ASR in 10 Japanese children with ASD and 34 without ASD. The electromyographic activity of the left orbicularis oculi muscle to pulse stimuli of 65 to 115 dB SPL, in increments of 5 dB, was measured to evaluate ASR. Average eyeblink magnitude, average peak startle latency of ASR for each acoustic stimuli intensity was evaluated. Quantitative autistic traits were assessed with the Social Responsive Scale (SRS) to analyze the relationship between startle measures. Magnitude of ASR to weak stimuli (70dB) , was greater in ASD individuals, and Peak startle latency was prolonged in ASD. These startle measures were associated with several subscale scores of SRS. Comprehensive investigation of ASR, including the magnitude of startle responses to weak stimuli and peak startle latency, might increase understanding of the neurophysiological impairments underlying ASD.