Abstract: Active constituents were isolated from the flower buds of Lonicera japonica Thunb. They were extracted with 70% alcohol, then fractioned successively with petroleum ether, ethyl acetate and n-butanol. The ethyl acetate part was repeatedly chromatographed on silica gel column and purified with ODS column. Nine compounds, namely loganin(1),sweroside(2),7-epi-vogeloside(3),7-epi-loganin(4),secoxyloganin(5),caffeic acid(6),p-hydroxybenzoic acid(7), β-sitosterol(8) and daucosterol (9) were obtained and their structures were deduced by comparison of their physico-chemical properties and spectral data with those of reference data. Compounds 4,5,6,7 were found for the first time in the flower buds of L. japonica Thunb., and compounds 1,4,5 were found to possess hepato- protective effect.