The author measured the microquantity of urinary protein after working by simplified method, previously reported in Part 1, and by the test paper method, and also examined it by the above method for the control of fatigued workers and those having of kidney diseases from 10102 workers in total of a shipbuilding yard during 4 years. The results obtained were as follows. 1) The screening-level of urinary protein excretion after working was estimated to be 0.25‰ from the excretion of urinary protein after 8-hour working on 971 workers. 2) During 4 years, 10102 total workers were checked by 0.25‰ of urinary proteinas to determine screeing-level of fatigued workers and those with kidney disease. As the result it was that 454 were of abnormal proteinuria in the first screening, and 411 of them recovered from abnormal proteinuria controlled by limitation of their overtime work for 1 moth. Using this method, it will be shown that the rate of recovery from the fatigue was 90.5 % . Therefore, it seems that the method above mentioned in Part 1, was a useful one for checking temporary fatigue. In the case of 43 workers, who did not recover from abnormal proteinuria although their overtime work was limited, they were taken as the second cotrol of limitation of overtime work for 1 month as described in the item 2, and for those who did not show any decrease in the protein content they were examined for kidney disease. Of these 43 examined 4 were found to be fatigued, 28 of them with anamnesis of kidney diseases, and 7 of them with severe kidney disease newly found. After successful treatment ot the new patients, they returned to their respective position, while the otheres reurned to their work on the advice of their physician in charge. It is reasonable to conclude that this microquantitaive determination method is useful for the control of fatigue in workmen as well as for the control of kidney direase.