This experiment was conducted with the object of finding out the instinct of smooth-rough type variation, which is a form of bacterial variation. Organisms used were same as Report 1-S. typhi 57-S and its isolated 57-R. Experimental method was the measurementof O(2) uptake and CO(2) evaluation by use of Warburg manometer, and at the same time detection of production by quantitative and paper chromatography of the various substrates. The results were as follows; 1. In type-S bacterium mainly glucose was analyzed by Embden-Meyerhof pathway. The amount of production of pyruvic acid from glucose under the system in which complete analysis was inhibited with addition of KCN, was twice that of R-type bacterium. 2. Under the same experiment of type-S bacterium, the production of glucose was detected by paper chromatography to be pyruvic acid only. 3. In type-R bacterium, mainly glucose was analyzed by Warburg-Dickens pathway. The amount of production of pyruvic acid from glucose under the system in which complete analysis was inhibited with addition of KCN, was one-half that of S-type bacterium. 4. Under the same experiment of type-R bacterium, the production of glucose was detected by paper chromatography to be, in addition to pyruvic acid, gluconic acid which is believed to be the result of glucose dehydrogenase system. Also, pyruvic acid was found in the production of gluconic acid. From the above experiment it was found that if S-type bacterium changes to R-type, Warburg-Dickens pathway and glucose dehydrogenase system will develop.