As objects for study, the following three types of work were taken: a) Work in a railway hospital---light labor. b) Work of baggage-transfer men at the station---medium labor. c) Maintenance work---heavy labor. Regarding the above three, I examined the worker's fatigue mainly by the Ogata's method and observed the development of the density of urine-protein and the quantity of it excreted per hour and also compared the influences on the urine-protein by giving water to the worker. The following results were obtined. 1) In the light labor, the density of urine-protein and the quantity of it excreted per hour did not increase. 2) In the medium and heavy labor groups, the density of urin-protein and the quantity of it excreted per hour did increase. 3) In all three, light, medium and heavy labor, as food and water given, the urine quantity increased and the density of urine-protein decreased. So, in putting the Ogata's method into practice, it is advisable to restrict the taking in of water and to observe both the density of urine-protein and the quantity of it excreted per hour. 4) In the light labor group it is presumed that the urine-protein is excreted comparatively constantly. 5) Testing by the Ogata's method, the fatigue could not be measured in the railway hospital worker, but in the work of the baggage-transfer men at the station and the maintenance worker a slight fatigue was noticeable.