Using cell-free extracts prepared from such strains of B. typhosa as S-type strain, R-type strain, SM-resistant strain and CM-resistant srain, of S(57), this experiment has been performed to determine enzymological properties of these extracts. The following are the results. 1. Cell-free extracts prepared from these four strains of S(57) by grinding with emery powder: These extracts prove to have respiratory activity on lactate, succinate, and fumarate. 2. Although four strains of S(57) do not show any marked difference in their respiratory activity on such oxidases as lactate, succinate, and fumarate, oxygen uptake per hour per mg of N in cell-free extract of R-type strain is greatest, followed by that of CM-resistant strain, S-type strain, and SM-resistant strain in the order mentioned. 3. Lactic oxidase contained in all these four extracts of S(57) has been verified to be an entirely different oxidase from that found in animal tissues, yeasts, and other bacteria. 4. The action of inhibitory agents, especially that of malonate, on resting bacteria differs markedly from the same on cellfree extracts; and it is indicated that this phenomenon is possibly caused by permeability of cell membrane of bacteria.