Phytochemical investigation on the whole herbs of Thalictrum delavayi Franch. (Ranunculaceae) led to the isolation of eleven compounds, including nine isoquinoline alkaloids (1–9) and two megastigmane-type norsesquiterpenoids (10–11). Tetrahydroisoquinoline (1) was a synthetic intermediate, newly identified as a natural product. Megastigmane-type norsesquiterpenoids (compounds 10 and 11) were isolated from the genus Thalictrum for the first time. The chemotaxonomic significance of these compounds was summarized. © 2019