The oral administration of glycine remarkably decreased the blood ethanol level in mice which had ingested ethanol, and a large amount of ethanol was retained in their stomachs. These effects were observed by the oral administration of glycine previous to the ethanol ingestion, and depended on the dose of glycine. An intravenous injection of glycine did not affect the ethanol absorption at all. These findings indicate that glycine suppresses the rate of ethanol absorption from the gastrointestinal tract. Glycylglycine, glycylglycylglycine and alanine showed the same effects, but glucose did not. However, ethanol absorption from the ligated stomach of mouse was inhibited not only by glycine but also by glucose. On the other hand, the rate of ejecting a pigment from the stomach to the small intestine was lowered by glycine, but not by glucose. Thus, glycine lowers the gastric emptying rate, resulting in the suppression of ethanol absorption from the gastrointestinal tract.