Natural products with insecticidal activities could be a valuable resource for the discovery of new insecticides. The Chinese bittersweet, Celastrus angulatus, is a traditional insecticidal plant which is widely distributed over the Yellow River and Yangze River basins in China. Since 1985, we have studied on  the bioactive compounds in the plant. By the activityguided fractionation, 51compounds have been isolated from the extract of the root bark and leaves. All the compounds belong to sesquiterpene ployol esters and pyridine alkaloids with the βdihydroagarofuran skeleton. A series of new dihydroagarofuran analogues were synthesized using difuranoβdihydroagarofuran and celangulin V as the starting materials, some of these derivates had higher insecticidal activity than celangulin V. The results of primary toxicology research indicated that the main action mechanism of the narcotic active component celangulin IV might be to block the conduction of insect neuromuscular excitatory junction potentials and inhibit the Ca²⁺ channel of the insects, and that the main action mechanism of the insecticidal component celangulin V might be to bind with the receptor in the midgut of the insect, change the structure of the cell membrane, and disturb the normal function of the membrane. Three formulations (0.2% celangulin emulsifiable concentrate, 0.15% celangulin microemulsion and 0.15%  celangulin micropowder) were conferred patent right, and 0.2% celangulin EC has been produced commercially.