From the polar fractions of a 70% EtOH extract of the flower buds of Lonicera japonica (Caprifoliaceae), ten constituents were isolated and identified as iridoid glycosides 7-dehydrologanin (7-ketologanin, 2), secologanin dimethyl acetal (3), (E)-aldosecologanin (centauroside, 5), dimethyl secologanoside (6), secoxyloganin (7) and epivogeloside (8). Other identified constituents were 1-O-$eta$-D-glucopyranosyl-(2S,3S,4R,8E/Z)-2-[(2R)-2-hydroxy(docosanoyl, tricosanoyl, tetracosanoyl, pentacosanoyl)amino]-8-octadecene-1,3,4-triol (1), uracil (4), D-mannitol (9), and sucrose (10). Among them, 1, 2, 4, and 10 were isolated for the first time from this plant.