In order to overproduce L-arginine, intergeneric protoplast fusion between Brevibacterium flavum and Corynebacterium glutamicum was performed. For the protoplast fusion, various amino acid analogs, sulfa drugs and/or purine base analogs resistant mutants were isolated from B. flavum ATCC 21493 and C. glutamicum ATCC 21831. The optimum conditions for protoplast fusion of these mutants were examined. Fusani MWE 9031 was found co accumulate a large amount of L-arginine in the culture medium. The concentration of accumulated L-arginine reached 32.5㎎/㎖ with a medium containing 10% glucose. Also the characteristics of culture condition in fusant MWE 9031 was investigated to compare with those of parental strains.