There has been found by author that the preserved blood transfusion results somewhat remarkable pathological changes in the renal functions without any evident clinical signs. In the patients of hypoproteinemia, anemia and dehydrated state there are seen temporary decreasings of urine flow after transfusion. This tendency is moremarkedly in the various kinds of untoward reactions. Thus the author studied on the pathological changes of renal functions by renal clearance method. 1. Type Ⅰ of pathophysiological changes in renal functions: This type of pathophysiological changes did not show any kinds of Oxford shunting and is seen in the patients of nearly normal state or anemia without untoward reactions. In this type there was seen the mechanism to maintain the glomerular filtration-function to compensate decreasing of renal blood flow which was resulted by dilatation of extrarenal blood vessels due to blood transfusion. In the other hand, there are seen, in the meaning of humoral mechanism, early adrenalin effects or early antiduretic hormon effects and late DOCA effects or decreasing of mineral excreations. 2. Type Ⅱ of pathophysiological changes in renal fonctions: This type means the presence of Oxford shunting Ⅰ in slight grade and is seen in the patients of hypoproteinemia and dehydorated state without untoward reactions. The disturbance in the course of inactivation of antiduretic hormon in liver. This disturbance as well as the decreasing of cortical reactions in epinephral glands results the abnormal renal circulations as Oxford shunting, even it is temporarily. 3. Renal functions in the fever reactions: In this untoward reaction, the predominant mechanism of renal function-change is homeostatic one which means the constriction of blood vessels in the region of internal organs. But homeostasis itsself do not bring about the abnormal renal circulation. In the patients of hypoproteinemia and dehydrated state, the fever reaction results the various type of Oxford shunting and severe decreasing or renal flow in cooperation of homeostasis and type Ⅱ of patho-physiological changes in renal function as over montioned. 4. Renal functions in the hemolytic reactions: There are seen the various kinds of Oxford shuntig in every cases of this untoward reactions and the durations of such abnormal renal circulation are more longer. Especially in the severe hemolytic reactions, the abnormal renal functions identify to that of shock reaction as Oxford shunting Ⅲ.