This study investigates the terpenoid components of Sambucus adnata Wall. and their vascular protective activities against hypoxia-induced endothelial cell injury. The chemical constituents of the ethyl acetate extract from the methanol extract of S. adnata was separated and purified, and the structures of the compounds were identified using multiple spectroscopic data. Human umbilical vein endothelial cells (HUVECs) were subjected to oxygen and glucose deprivation to simulate hypoxia-induced endothelial cell injury, and the potential activities of compounds were evaluated. Effects on HUVECs viability were assessed via MTT assay. Eleven triterpenoid compounds were isolated and identified, including urs-12-ene-3β,17β,22β-diol (1), (1S,5S,10R)-1-hydroxyeudesma-4(14),7(11)-dien-8-one (2), 3β,13β-dihydroxyurs-11-en-28-oic acid (3), ursolic acid (4), 1-hydroxyeudesma-4(14),7(11)-dien-8-one (5), capillosanane Z (6), 2-desoxy-4-epi-pulchellin (7), 3-hydroxy-β-damascone (8), 3-hydroxy-β-ionone (9), 4, 5-dihydroblumenol A (10), and 6S,9R-blumenol B (11). Compound 1 is identified as novel triterpenoids, and compound 2 as a new eudesmane sesquiterpenoid. Additionally, compounds 3 and 5-11 are previously unreported in the Sambucus genus. Notably, compounds 2 and 6 significantly protected against hypoxia-induced injury in HUVECs, with EC₅₀ values of 38.77 ± 4.82 and 29.60 ± 7.03 μmol/L, respectively. These results indicate that compounds 2 and 6 possess protective activity and may be the potential active components in the ethyl acetate extract of S. adnata.