The author studied the action of various inhibitors and antibiotics on the glutamaterespiration of staphylococci under the consideration of physiological structure of the cell. Staphylococcus citreus and aureus (Terashima) were used as the test organisms, and L-glutamic acid as the substrate. The results were as follows: 1) Thionine, sodium arsenite and 8-hydroxyquinoline inhibited the respiration of intact cells of staphylococci markedly, but did not inhibit that of cell-free extracts. The inhibitive action of these three sorts of inhibitors was stronger on Staph. aureus (Terashima) than on Staph. citreus. 2) In intact cells, the inhibition of respiration by potassium cyanide and sodium azide was not restored by addition of thionine. In cell-free extracts, however, the inhibition by these two sorts of inhibitors was well restored by thionine. 3) By addition of thionine, the inhibition of the respiration of cell-free extracts by octanole was not so well restored as that by cyanide or azide. 4) 2, 4-Dinitrophenol inhibited the glntamate-respiration of both of the intact cells and cell-free extracts. 5) Of all the antibiotics tested, aureomycin was the only one which noticeably inhibited the glutamate-respiration of staphylococci.