A new triterpenoid saponin, oleiferasaponin A₁, was isolated from tea seed pomace (Camellia oleifera Abel). The structure of oleiferasaponin A₁ was elucidated on the basis of chemical and physicochemical evidence and was found to be 22-O-cis-2-hexenoyl-A₁-barrigenol 3-O-[β-D-galactopyranosyl(1→2)] [β-D-glucopyranosyl(1→2)-α-L-arabinopyranosyl(1→3)]-β-D-glucopyranosiduronic acid. PC12 cells injured with H₂O₂ were used as the model to test the protective effects of oleiferasaponin A₁. The results indicated that oleiferasaponin A₁ can potentially prevent the H₂O₂-induced cell death of PC12 cells.