Objective To study the chemical constituents in the seeds of Euphorbia lathyris.MethodsCompounds were isolated by methods of column chromatography(silica gel,including reversed phase),Sephadex,and recrystallization.On the basis of spectroscopic methods including IR,MS,NMR,and X-ray,structures of compounds were confirmed.Results Twenty-two multi-type compounds were isolated from ethanol extract in the seeds of E.lathyris.Their structures were identified as 5,15-O-diacetyl-3-O-phenyl-6(17)-epoxylathyrol(1),5,15-O-diacetyl-3,7-O-dibenzoyl-7-hydroxylathyrol(2),5,15-O-diacetyl-3-O-benzoyl-lathyrol(3),20-O-hexadecanoyl-ingenol(4),3-O-hexadecanoyl-ingenol(5),15,17-O-diacetyl-3-O-cinnamoyl-17-hydroxyjolkinol(6),5,15,17-O-triacetyl-3-O-benzoyl-17-hydroxyisolathyrol(7),5,15-O-diacetyl-3-O-nicotinoyl-lathyrol(8),5,15-O-diacetyl-3-O-benzoyl-7-O-nicotinoyl-7-hydroxy-lathyrol(9),ingenol(10),lathyrol(11),esculetin(12),?-sitosterol(13),benzene-1,2,3-triol(14),palmiticacid(15),2,3-dihydroxypropyl icosanoate(16), 2,3-dihydroxypropyl oleate(17),2,3,4-trihydroxybutyl hexadec-3-enoate(18),aurantianide acetate(19),benzoic acid(20),p-hydroxybenzoic acid(21),oleic acid(22).Conclusion Among these,compounds 10,11,1419 are obtained from this plant for the first time and compounds 1-3 are the main diterpenes.