Using the standard strains of St. aureus, albus and citreus stocked in our laboratory, the author pursued the modes of glucose oxidation of bacteria. either by still standing culture or shaking culture in liquid medium with glucose or gluconate as the C-source, and obtained the following results: 1. Oxidation abilities of gluconate of these bacteria, cultured in the medium with glucose as the C-source by still standing method, are low shaking method the oxidation of gluconate increases relatively high irrespective of the iength of culture. Furthermore, considering inhibitory effect of DNP against the oxidation of glucose, in the still standing culture the oxidation of glucose may be thought to depend mainly on the E-M pathway and in the shaking culture it develops to the W-D pathway or glucose ➝ gluconate ➝ 2-keto-gluconate (or 5-ketogluconate) pathway. 2. In the case where gluconate is used as the C-source, the oxidation of gluconate is relatively great in shaking culture and even in stationary culture; but the oxidation of glucose in this case proved to be exactly identical with that where glucose has been used as the C-source. 3. The Adaptability to the C-source of medium of bacteria belonging to Staphylococcus seems to be in general of relatively less, especially the adaptability to ribose, and gluconate is. The Oxidation of ribose and gluconate upon the phase of growth rather than the C-source of the medium.