This article provides an overview of the nutritional requirements of larval and juvenilePenaeus japonicus, referring to past studies briefly and focusing on recent studies on proteins, lipids, and other essential nutrients. Also, the quantitative requirements of nutrients in crustacean species were critically evaluated in relation to net nutrient intake inP. japonicus. Like fish and other vertebrates, larval and juvenileP. japonicusrequire 10 essential amino acids, essential fatty acids, vitamins, and minerals for their normal development, growth, survival, and reproduction. In contrast to fish and other vertebrates, however, both larval and juvenile prawns require dietary sources of sterols and some phospholipids as indispensable nutrients. Metabolic studies on juvenileP. japonicususing radioactive lipids suggested that dietary phospholipids take part in the transport of dietary lipids, especially cholesterol, through the hemolymph in their body. In nutritional studies, leaching or loss of dietary nutrients into the water is an obstacle to development of valid conclusions on nutrient requirements ofP. japonicus, particularly the larvae.