Intravenous hyperalimentation (IVH) needs 24 hour infusion everyday without an interruption. Insulin and glucagon are not physiologically secreted. Metabolic rhythm in the body is changed. Protein synthesis and nitrogen balance may be disturbed. For improvement of the metabolic disturbance in IVH, intermittent intraportal hyperalimentation was investigated. Eight Beagles weighed about 10 kg and mongrel dogs weighed 18 kg were used. Glucose and amino acids were given 12.0 g/kg and 2.5 g/kg, respectively. Those were infused into the portal vein for 10 hours every day. During the next 14 hours infusion was not performed at all. Fat was intravenously given 1.5 g/kg as emulsion every day. The levels of insulin and glucagon in the portal vein and the uptake rate of glucose and amino acids in the liver were investigated during administration of the nutrients. After 30 days the dogs were sacrificed and pathological examination was performed. Insulin and glucagon levels were almost physiologically changed. The uptake rate of amino acids into the liver was a high level of 52%. In spite of low level of 162 in non-protein calorie to nitrogen ratio, nitrogen balance remained in 106 +/- 23 mg/kg/day. The body weight increased by 3.6% on the average (p less than 0.01) and the serum protein levels significantly increased (p less than 0.01). In one out of 8 dogs, minute thrombosis and slight sclerosis of the portal vein were found. The liver showed no histological changes. In conclusion, the intermittent portal hyperalimentation seems to be a possible and excellent method of nutrition.