Objective:To investigate the chemical components of the dry fruits of Forsythia suspense(Thunb.)Vahl and their anti-inflammatory activities. MethodsChemical compounds were isolated from the dry fruits of Forsythia suspense using silica gel, Sephadex LH-20 and MCI chromatography, in combination with isolation techniques including ODS middle-pressure preparative chromatography, preparative thin layer chromatography and preparative liquid chromatography, and structures of the components were identified with mass spectrometry and nuclear magnetic resonance spectroscopy. The inhibitory effect of some components on nitrix oxide(NO)secretion were determined by using induced model on mouse macrophages RAW 264.7.  Results:Thirty compounds were isolated and the compounds including 4-allylcatechol (1), 19-hydroxy-13-oxo-15,6-dinor-ent-labda-8 (17)-ene (2), 18-hydroxy-13-oxo-15,6-dinor-cleroda-3,4-ene (3), 3,3-oxo-15,6-dinor-ent-labda-8 (17)-ene (4), dammarendiol II (6), serralabdane B (9), and (4S, 9R, 10R) methyl 18-carboxy-labda-8,3 (E)-diene-15-oate (15) were isolated for the first time from genus Forsythia. Experimental results of the cell inflammation model showed that the compounds 2~4, (±)-pinoresinol (16) and rengyolone (18) inhibited NO secretion.  Conclusion:8 diterpenoids were isolated from the dry fruits of Forsythia suspense, and anti-inflammatory activities of compounds 2~4 were reported for the first time.