The chemical constituents and cytotoxic activity of grown Fructus Forsythiae were studied.The compounds were isolated and purified by silica gel column chromatography,Sephadex LH-20 column chromatography,ODS column chromatography and semi preparative HPLC.The structures of the compounds were analyzed by 1H NMR,13C NMR and ESI-MS.Seventeen compounds were identified as adoxosidic acid(1),phillyrin(2),rutin(3),(+)-pinoresinol-4-O-β-D-glucoside(4),(+)-epipinoresinol-β-D-glucoside(5),(+)-rpipinoresinol-4′′-β-D-glucoside(6),forsythoside A(7),lianqiaoxinside(8),calceolariolside B(9),(7R,8S,7′R,8′S)-8-hydroxypinoresinol-4-O-β-D-glucopyranoside(10),calceolarioside A(11),plantainoside A(12),forsythoside E(13),lariciresinol 4′-O-β-D-glucoside(14),forsythoside G(15),forsythoside H(16),(+)-pinoresinolmonomethyether-β-D-glucoside(17).Compounds 4,6,9,10,14,17 were isolated from this genus for the first time.The antitumor activities of 17 compounds were screened by MTT assay.The results showed that compounds 1-17 did not inhibit the proliferation of tumor cells.