Conjugate trienoic acids (CTA) occurred in triacylglycerols (TGs) of the seed oils of Trichosanthes kirilowii, Momordica charantia and Aleurites fordii, and they were easily converted to their methyl esters in a mixture of sodium methoxide-methanol without any structural destruction. The main fatty acids in triacylglycerol (TG) fraction of the seed oils of Trichosanthes kirilowii are C18:2Ω6 (32.2 mol %), C18:3 9c.11t,13c (38.0 mol %) and C18:1Ω9 (11.8 mol %), followed with C16:0 (4.8 mol %) and C18:0 (3.1 mol %). The TG fraction was resolved into 20 TG molecular species according to the partition number (PN) by reversed-phase (RP)-HPLC. The main TG species were DTc2, MDTc and D2Tc, of which amounts reached 63 mol % of total TG molecular species. The TG sample was fractionated into 11 fractions according to the number of double bond in the molecule by Ag+-HPLC and the species of DTc2, MDTc and D2Tc were also eluted as main components. The TG species containing CTA showed unusual behaviours in the order of elution by HPLC ; first, TG moleular species of DTc2 (D; dienoic acid, Tc; punicic acid, Tci; α-eleostearic acid, M ; monoenoic acid, St; stearic acid) was eluted earlier than Mtc2, although they have the same PN number of 40, and, secondly, the species of DTci2 with eight double bonds was eluted earlier than that of D2Tci with seven double bonds. Intact TG of the seed oils of Momordica charantia contained mainly fatty acids such as C18:3Ω9c,11t,13t (57.7 mol %), C18:1Ω9 (17.4 mol %), C18:0 (12.3 mol %) and C18:2Ω6 (10.6 mol %), and was classified into 13 fractions by RP-HPLC. The main TG species were as follows ; MTci2 [(C18:1Ω9)(C18:3 9c,11t,13t)2, 39.1 mol %] and StTci2 [(C18:0)(C18:3 9c,11t,13t)2, 33.9 mol %] comprising about 73 mol % of total TG species, accompanied by DTci2 [(C18:2Ω6)(C18:3 9c,11t,13t)2, 7.3 mol %], D2Tci [ (C18:2Ω6)2(C18:3 9c,11t,13t), 3.6 mol %] and MDTci [(C18:1Ω9)(C18:2Ω6)(C18:3 9c,11t,13t), 3.5 mol %]. Simple TG species of Tci3 [(C18:3 9c,11t,13t)3] was present in a small amount of 1.4 mol %, but other simple TG species were not detected. The TG was also resolved into 11 fractions according to the number of double bond by Ag+-HPLC, and the species were mainly occupied by MTci2 [(C18:1Ω9)(C18:3 9c,11t,13t)2, 39.4 mol %] and StT-ci2 [(C18:0)(C18:3 9c,11t,13t)2, 35.4 mol %] DTci2 species with eight double bonds was also developed faster than D2Tci one with seven double bonds as indicated in the analysis of TG of the seed oils of T. kirilowii, and MTci2 species with cis, trans, trans-configurated double bond was eluted earlier than MTc2 species with cis, trans, cis-configurated double bond. The main components of fatty acid in total TG fraction isolated from the seed oils of of Aleurites fordii were in the following order ; C18:3 9c,11t,13t (81.2 mol %)〉 C18:2Ω6 (8.5 mol %)〉 C18:1Ω9 (5.4 mol %). With resolution of the TG by RP-HPLC, eight fractions such as Tci3, Dtci2, D2Tci, MTci2, PTci2 (P; palmi..