The lipid components of the gonad of sea urchin Hemicentrotus pulcherrimus, ark shell Scapharca bro-ughtonii and "Gaebul" (Korea name, a worm) Urechis unicinctus were investigated. The total lipid (TL) contents of the sea urchin, the ark shell and the "Gaebul" were 6.10, 0.67 and 0.79%, respectively. The percentages of phospholipid (PL) in TL were higher in the "Gaebul"(72.4%) and ark shell(64.9%) compared to the sea urchin (41.7%). The major lipid classes of PL were phosphatidylcholine and phosphatidylethanolamine, and the former was rich in the sea urchin (56.2%) and the latter in the "Gaebul"(34.4%). In the class of non-polar lipid (NL), the major lipid classes were different from species ; the sea urchin was rich in triglyceride(TG, 89.0%), the ark shell rich in TG (69.2%) and cholesterol (ST 26.8%) and the "Gaebul"rich in ST (70.7%). The prominent fatty acids of the sea urchin were 16 : 0, 14 : 0, 20 : 5n-3, 20 : 4n-6 and 20 : 4n-6 and 20 : 2NMID(non-methylene interupted dien). The percentage of 20 : 4n-6 was the highest of the investigated invertebrates, accounting for 19.8% in PL, but 22 : 6n-3 was not detected in the sea urchin. In case of the ark shell, the prominent fatty acids were 16 : 0, 18 : 0, 20 : 5n-3, 22 : 6n-3 and 22 : 2NMID, especially 22 : 6n-3(9.58%) was richer compared to that of the "Gaebul". The prominent fatty acids of the "Gaebul"were 20 : 5n-3, 16 : 0, 18 : 0 20 : 1n-9, 16 : 1n-7 and 14 : 0. The percentage of 20 : 5n-3 (22.0%) was highest in the PL of the "Gaebul"among the three invertebrates. These differences in the lipid components of all the sample is considered to be due to the different food habits and environmental condition of the invertebrates.