The chemical constituents of the frutis of Citrus medica L．were isolated and purified by silica gel, sephadex LH-20 and RP C-18 chromatographic methods and their structures were elucidated mainly by NMR and MS evidences. Thirteen components were obtained and identified as limettin (1), scopoletin (2), β-sitosterol (3), obacunone (4), nomilin (5), limonin (6), isoobacunoic acid (7), hesperetin (8), daucosterol (9), 1-O- ` ( β-D-glucopyranosyl ) – (2S , 3S , 4E , 8E) – 2 - [(2'R) -2′- hydroxyhexadecanoylam ino ] -4.(E), 8(E) - octadecadiene-1, 3-diol (10), pruning (11), naringin (12), hesperidin (13).