Abstract: The chemical constituents in the seeds of Trichosanthes rubriflos were isolated and purified by silica gel column chromatography, Sephadex LH-20 column chromatography, high performance liquid chromatography and other separation methods. The structures were characterized by various spectroscopic. Four compounds identified as 7,24-dioxo-10α-cucurbita-5,25-dien-3β-ol ( 1 ), cucurbita-5,25-diene-3β,24-diol ( 2 ), (E)-11-methoxy-11-oxoundec-2-enoic acid ( 3 ), (12S,13S,Z)-12-hydroxyoctadec-9-en-13-olide ( 4 ). Compound 1 and 2 are new compounds and compound 3 is a new natural compound, while compound 4 was isolated from Trichosanthes for the first time.