Venous return blood volume and the factors affecting it are divided into five main areas: first, changes in the mean filling pressure of the body circulation, that is, changes in blood volume and vascular volume. Usually emphasize a small number of times a day to drink water, is to increase the replacement of lost water, such as urine, sweat, etc.. The higher the mean filling pressure of the circulation, the higher the venous return flow when all other factors are constant. Second, the stronger the heart contraction force, the more venous return flow, such as athletes after non-stop exercise, heart contraction force is relatively strong. Third, the change of body position, that is, the effect of gravity. If the upright position suddenly turn to lying position, the venous return flow is increased. Fourth, the skeletal muscle extrusion, skeletal muscle alternate contraction and diastole can promote venous return. Fifth, the respiratory movement has an effect on the venous return flow, and the respiratory movement enhances the venous return flow. There are five main factors that affect the return blood volume.