The kidney function test by means of the clearance method was done on various medical diseases in the wide scope and the correlation between those diseases and their kidney function was observed. And the results were as follows. 1. The low value of GFR was specific in acute glomerulonephritis, the decline of RPF was specific in chronic glomerulonephritis, and both of GFR and RPF declined in nephrosis. In kidney tuberculosis, both of GFR and RPF were declined or normal in some of them, but it related to the attacked degree of disease. No remarkable changes of them were observed on kidney stone. 2. The rise of GFR was observed on Basedow's disease, the fall of GFR was observed on myxoedema with RPF and the rise of FF was observed on the former. In diabetes, both of GFR and RPF were normal or slightly rised. In Cushing's syndrome, GFR was a little decline, RPF was decreased and the rise of FF was observed. In uremia, the decrease of GFR, RPF and FF, especially the extreme decline of RR, was observed. 3. In essential hypertension, both of GFR and RPF declined, and the decline of RPF was remarkable and the rise of FF was observed. In renal hypertension, FF was declined by the remarkable decline of GFR. 4. In heart failure without compensation, both of GFR and RPF were low and those were within normal value in heart failure with compensation. In subacute bacterial endocarditis, they showed the different attitude before or after the treatment. 5. No abnormality of them was observed on stomach ulcer. 6. In hepatitis, the decline of RPF in the II form by H. Eppinger, the rise of it in the III form by H. Eppinger were observed and there were normal value, the increase of GFR and the rise of FF by the decrease RPF in liver. In livercirrhosis, it was in normal limit, because it might be at the compensative stadium. No fixed tendency was not observed on cholecystopathy. 7. In pleurisy with fluid, a little rise of RPF, the decrease of FF and the rise of RR were observed, and normal value of them and the decrease of RR were observed on pleurisy without fluid. In lung tuberculosis, they were in normal limit. 8. The decline of FF and a litte high RPF in infectious mononucleosis, a little decrease of RPF in thrombosis of splenic vein, the remarkable low value of GFR and GPF in leukemia, the rise of RPF and the decline of FF in hemorrhagic purpura were observed, but their cases were very few. 9. As for the kidney function of tonsillitis with or without tonsillectomy, both of GFR and RPF were declined at 1 week after the tonsillectomy and the increasing tendency of RPF was observed on the one case which could be checked at 2 week after the tonsillectomy.