Enteral nutrition is a method of nutritional support. If the gut works, its use is recommended for nutritional support. Enteral nutrition has several advantages; low cost, more physiologic, and prevention of mucosal atrophy and maintenance of gastrointestinal immunity. Enteral formula is the medical food used for enteral nutrition. Several types of enteral formula are used in clinical practice. I will hereby introduce the types and selection of enteral formula.