A L-histidine-high-producing mutant was obtained from Brevibacterium flavum by means of mutagenesis. When incubated at 30℃for 72hr, it could accumulate about 128.28mg·L -1 L-histidine in the medium containing 150g·L -1 glucose, 35g·L -1(NH 4) 2SO 4 and 10g·L -1 peptone.