In order to know the relationship between the value of R. M. R. and the quantity of urinary protein, the author measured minute quantities of proteins excreted in the urine under the load of the bicycle ergometer by simplified method as reported in Part 1. The quantities of urinary protein before and after working in the each shop of a shipbuilding yard, were also measured, and the following results were obtained. 1) Physical exercise was given on a bicycle ergometer and urinary protein was measured. It was observed that the quantities of urinary protein increased in parallel with the value of R. M. R. ranging from 1 to 7. 2) In each shop of the shipbuilding yard, it was also observed that the quantities of urinary protein after working, paralleled with the values of R. M. R.