The chemical constituents from the pomace fraction with water extract of Siraitia grosvenorii,and the anti-inflammatory activity in vitro were studied.The chemical constituents from the pomace fraction of Siraitia grosvenorii were isolated with various chromatographic separation techniques,and their structures were determined by entirely analyzing MS and NMR spectrums,there are oleanolic acid 28-O-β-D-glucopyranoside (1),oleanolic acid 3-O-β-D-glucuronyl-6′-ethyl ester (2),(3α)-7-oxomultiflor-8-ene-3,29-diol 3,29-dibenzoate (3),3,29-O-dibenzoyloxykarounidiol (4),isomultiflorenol (5),curcasinlignan B (6),urolignoside (7),diospyrosin (8),evofolin B (9),4′-hydroxyphenyl ethyl vanillate (10),aurantiamide (11),kaempferol-7-O-α-L-rhamnoside (12),kaempferitrin (13),kaempferol-3-O-β-D-glucopyranosyl-7-O-α-L-rhamnopyranoside (14),kaempferol 3-O-α-L-rhamnoside-7-O-β-D-xylosyl(1→2)-O-α-L-rhamnoside (15),sagittatin A (16),cucurbita-5,24-diene-3β-ol (17),balsaminol E (18),soya-cerebroside Ⅰ (19),β-sitosterol (20),β-daucosterol (21),7α-hydroxycholesterol (22),2E-4-hydroxy-nonenoic acid (23),vanillain (24),p-hydroxy-benzeneethanol (25),β-hydroxypropiovanillone (26).Compounds 2 and 6-11 were first isolated from Cucurbitaceae and compounds 1,3,4,14-16,18,19 and 22-26 were first isolated from Siraitia.Compounds 1-26 were preliminarily examined for anti-inflammatory activity in vitro,compounds 4,5,7,13,19 and 21 suppressed the production of TNF-α,compounds 13 and 21 both inhibited the production of IL-1β and IL-6,compounds 7,19 and 22 inhibited the production of IL-1β,compound 5 inhibited the production of IL-6.