One new lignan, loniceralanside A (1), together with three known compounds (2-4), were purified from Lonicerae Japonicae Flos. Their structures were determined by HR-ESI-MS, 1 D and 2 D NMR data. Compounds 2-4 were separated from the plant for the first time. The biological test showed that compound 1 had significant anti-inflammatory activity with inhibiting the release of β-glucuronidase induced by platelet-activating factor (PAF) in rat polymorphonuclear leukocytes (PMNs) (IC50 = 3.05 µM).