The effects of a new enteral diet (ED-9) that was mainly composed of BCAA enriched amino acids, MCT and maltose were examined. Rats were subjected to small bowel resection and were administered two different formula for 7 days. The animals were divided into the following four groups : Sham operation and ED-9 (Group A), sham operation and control diet (Elental) (Group B), small bowel resection and ED-9 (Group C), and small bowel resection and control diet (Group D). Body weight loss after operation was similar in both ED-9 and control diet groups. Nitrogen balance and uninary 3 Methy1-histidine excretion demonstrated that ED-9 tended to improve protein preservation. Rats given ED-9 showed elevated ketone bodies and plasma BCAA level but these levels were not extraordinarily high. In conclusion, the formula of enteral nutrition (ED-9) was as effective as Elental on postoperative nutrition in rats.