Studies on deaminization have been made of blood, urine and tissues of dogs surviving complete hepatectomy 8-30 hrs. In no case deaminization occurred after removal, as demonstrated by recovery of amounts of amino acids in blood, urine and tissues approximately equal to the anticipated formation of urea had the animal been normal. If amino acids were injected, the entire amount of amino-acid N was recovered unchanged in blood, urine and tissues many hours later. In addition to complete recovery of unchanged amino acids, no urea is formed in the absence of the liver, and ammonia formed following hepatectomy is not derived from amino acids in the body in the absence of the liver. Also, no glucose is formed from amino acids after hepatectomy. Deaminization of amino acids in the dog is entirely dependent on the presence of the liver, since deaminization ceases completely as soon as it is removed.