In March, 1951, the new patrol system of policemen was established in Japan.On the 13 patrolmen of Yodobashi Police Station in Tokyo from June 26 to July 10, 1951, our experiments were conducted.Urine was collected each 2-3hrs. successively, (3) Takeya-Kawada's fatigue reaction of urine, that is, a protecting colloid reaction of urine, was examined. To know the protecting power of urine against the precipitation of congo-red pigment, the concentration of the unprecipitated congo-red pigment in urine were estimated by the Takeya-Kawada's method. The volume of ketoenol substance in 10cc of urine by Hamazaki's method, the inorganic phosphorous contents in urine by (8) Shinowara-Jones-Reinhart's method, the volume and the pH of urine were estimated. The subjective symptomes were recorded also.The results were as follows:(1) The concentration of the unprecipitated conge-red pigment in urine by the Takeya Kawada's method are shown in Tab. 2. The average was 33-57% in the daytime work, 23-48% in the afternoon work and 48-82% in the night work.(2) The volume of keto-enol substance in 10cc of urine by Hamazaki's method were 0.008-0.010cc in the daytime work, 0.006-0.010cc in the afternoon work, and 0.034-0.162cc in the night work. (Tab. 6.)(3) The inorganic phosphorous concentration in urine were 0.419-0.504mg/cc in the afternoon work and 0.681-1.130mg/cc in the night work. (Tab. 4. 5.)(4) The pH of urine was 6.0-6.2 in the afternoon work and 5.7-5.8 in the night work. (Tab. 4. 5.)(5) The volume of urine per hour was 46.3-70.9cc in the afternoon work and 21.7-48.9cc in the night work. (Tab. 4. 5.)From the above results, we could see the fact that the daytime work and the afternoon work caused middle grade of fatigue, while the whole night work caused fatigue of middle to high grade. (Fig. 1. Tab. 6.)The pH and the volume of urine was lower in the whole night work than in the afternoon work. But the inorganic phosphorous concentration in urine increased more in the whole night work that in the afternoon work.