To analyze of fatty acid compositions in eri silkworm pupa oil and to provide scientific basics in the comprehensive utilization of eri silkworm pupa.Method: Crude lipids were extracted by organic solvent,then gas chromatography-mass spectrogrophy(GC-MS) and gas chromatography(GC) were used in the analysis of fatty acid.Result: The lipid of eri silkworm pupa is relative less(19.16%).The fatty acid compositions are C18∶3(43.41%),C16∶0(21.15%),C18∶1(11.59%),C18∶2(10.28%),C18∶0(8.08%),C16∶1(1.88%),C14∶0(0.93%),C15∶0(0.31%),C12∶0(0.16%)and cyclopropaneoctanonic acid(0.16%).The most abundant fatty acid is C18∶3(57.63%),and C16∶0(20.62%),C18∶1(7.68%),C18∶2(6.28%) and C18∶0(3.38%) are less.