Abstract: The experiment is to investigate the chemical constituents in rhizome of Lactuca laciniata. 12 compounds were separated by silica gel column chromatography and their structures were determined by spectroscopic experiments.They were identified as (2S)-1-O-heptatriacontanoyl glycerol (1), (2S,3S,4R,10E)-2-[(2R)-2-hydroxyl tetracosanoylamino]-10- octadecene-1,3,4-triol (2), 11β,13-dihydrolactucin acetate (3), lactucin (4), lactuside B (5), lactucopicrin (6), oleanolic acid (7), hexadecanoic acid (8), quercetin (9), friedelin (10), ursolic acid (11), octanedioic acid (12). Compounds 1,2,4,6-12 are separated from this plant for the first time and compounds 1 and 12 are isolated from the genus for the first time.

Key words: Lactuca laciniata, Compositae, 11&beta, ,13-dihydrolactucin acetate, lactuside B, quercetin