High-energy food (HEF) has a higher energy density than common food. Semi-fluid food is between solid and fluid food such as porridge, soymilk curds and meat emulsion. HEF has an advantage of smaller volume for a given energy, so is more convenient for people to carry and convey, which can lead to extensive use in military actions, aviation, tourism and exploration. However, till now, what people often find in the market is solid HEF. Some people have difficulty in accepting or cannot eat such solid food. Common fluid foods contain lower energy which cannot meet the demands of the special cases. Therefore it is necessary to develop a semi-fluid high-energy food (SHEF). This paper studied preparation technology of SHEF from protein hydrolysates which were made by enzymatic hydrolysis of lean meat and soy protein. Cooked lean meat was found to be more suitable for preparing SHEF than uncooked lean meat by comparing both as substrates of protease. Starch and oil were found to be main factors influencing their viscosity. Three kinds of SHEF (sweet, peppery and salty) of different tastes were developed by means of combining sensory evaluation with mentioned methods. The range of viscosity at 25 degreesC are 0.2135-0.3069 Pa s and its energy density can reach over 3.3 kcal/g. (C) 2003 Elsevier Science Ltd. All rights reserved.