Open-tubular gas chromatographic analysis (GLC) of fatty acids from the seed lipids of Aquilegia vulgaris (I), A. longissima (II), A. hybriba hort (III), Delphinium Ajacis (IV), and Nigella damascena (V) belong to Ranunculaceae have been carried out. The unusual fatty acids found in I, II, and III were trans-5, cis-9, cis-12-octadecatrienoic acid (t5, c9, c12-18 : 3) (neutral lipids 5659%, and polar lipids 3540% in I and II), t5, c9-18 : 2 (0.52.6%), and t5-16 : 1, t5-18 : 1 and t5, c9, c12, c15-18 : 4 (each less than 1%). These unusual acids have not been found in IV and V. The usual acids, 16 : 0, c9-18 : 1 and c9, c12-18 : 2, were found as the major constituents with the minor constituents, 14 : 0, 15 : 0, c7 and c9-16 : 1, 18 : 0, c11-18 : 1, c9, c12, c15-18 : 3, c11-20 : 1 and c11, c14-20 : 2 in common. The structures of the 5-olefinic acids were established by the comparison of the retention data in GLC of the cis-5 and trans-5 olefinic acids and their partially hydrogenated products on SP 2300 and SP 2340 liquid phases, and 13C-NMR spectra of them. The fatty acid composition of aquilegia seed lipids was a little changed by the germination.