The composition, nutritional evaluation and clinical trials of a nutritionally complete enteral preparation were presented. It was composed of glucose oligosaccharides, emulsified fat, solubilized proteins, twelve vitamins, certain minerals and trace elements. Rats were forced to negative nitrogen balance by means of protein-free diet. Body weight and serum total protein declined accordingly. When the feed was changed to this preparation in one group, and a routine one with equal nitrogen content in another, nitrogen balance was turned to positive, body weight increased, serum total protein returned to normal in both groups. The increments of nitrogen balance and body weight were, however, higher significantly in the group fed with the preparation than that with routine diet. The biological value, net protein utilization and protein efficiency ratio of the solubilized proteins in the preparation were higher than casein in the routine feed. Twenty surgical patients having the preparation as the sole source of nutrients could take around 8.37MJ(2000 kcal)a day. Nitrogen balance turned from negative to positive in an average time of 3.6 days. Body weight, serum total protein, serum albumin were all increased. Fourty patients took this as dietary supplement and the similar results were observed too. Clinical effects were excellent in all cases, especially for healing of surgical wounds and fistula. Incidence of diarrhea was 3.3%.