An L-glutamic acid producing microorganism which is constructed by incorporation into a recipient strain of the genus Brevibacterium or Corynebacterium of a hybrid plasmid having inserted therein a DNA fragment with genetic information related to L-glutamic acid production which is derived from a donor strain of the genus Brevibacterium or Corynebacterium, is useful for the production of high levels of L-glutamic acid by fermentation.