Abstract: Some results from the study of the biological effect of high level broad-band noise field (165-173 dB SPL) on guinea-pigs were presented in this paper. The lethal time of the guinea-pigs under varies sound levels was determined. The experimental results showed that when the sound level is increased by 3 dB, the lethal time of guinea-pigs is decreased to half, and its lethal noise-dose is approximately a constant, which is about 33 J/mm.