Abstract: The present study was designed to determine the chemical constituents of Delphinium caeruleum Jacq. ex Camb.. The chemical constituents were isolated and purified by column chromatography with silica gel, ODS, and Sephadex LH-20. Their structures were elucidated by IR, MS, and NMR. Ten compounds were obtained and identified as caerudelphinine A ( 1 ), lycoctonine ( 2 ), talitine B ( 3 ), talitine A ( 4 ), talitine C ( 5 ), tatsienine-V ( 6 ),d-magnoflorine ( 7 ), 2-trimethyl-ammonio-3-(3-indolyl) propionate ( 8 ), vakhmatine ( 9 ), and delatisine ( 10 ). Compound 1 was a new lycoctonine-type C19-diterpenoid alkaloid, and compounds 4 - 10 were isolated from this plant for the first time.