Three new diterpenoid alkaloids (DAs), including two lycaconitine-type C19-DAs tatsiedines A and B (1 and 2) and a vakognavine-type C20-DA tatsiedine C (3), have been isolated from the whole plants of Delphinium tatsienense Franch. (Ranunculaceae), a folk medicine for the treatment of wind-toxin syndrome in China. Their structures were established on the basis of extensive spectroscopic analyses. The isolated compounds were evaluated for their potential anti-inflammatory effects against NO production using LPS-stimulated RAW 264.7 macrophages. © 2020 Phytochemical Society of Europe