The present experiments were conducted to investigate the moisture content, lipid class and fatty acid composition in mature ovary and early embryo of Portunus pelagicus. The results indicated that: (1) Although the early embryo of P. pelagicus had higher moisture content than that of mature ovary, the higher total lipid/wet tissue could be found in the mature ovary than that of early embryo; (2) There were no significatn differences in the triacyglycerol (TG) and phospholipids (PL) contents between mature ovary and early embryo, however, the early embryo had higher free fatty acids and cholesterol contents than the mature ovary. This could be explained by the hydrolyzation of TG and PL; (3) There were twenty seven identified fatty acids that could be detected in the both mature ovary and early embryo. The significant differences existed only in 15∶〗0, 14∶1n7, 20∶1n7 and 18∶3n3 between mature ovary and early embryo while the main fatty acids were 16∶0, 18∶0, 16∶1n7, 18∶1n9, 20∶5n3 and 22∶6n3 for both tissues.