A new ellagic acid derivative 3,3′-di- O-methylellagic acid 4 ′-α-l-arabinopyranoside (1), with 9 known compounds identified as 3,3′-di- O-methylellagic acid (2), 3,3′-di- O-methylellagic acid 4′-α-d-arabinofuranoside (3), 3,3′-di- O-methylellagic acid 4′ -β-d-glucopyranoside (4), 3,3′-di- O-methylellagic acid 4 ′-β-d-xylopyranoglucoside (5), 3,3′,4-tri- O-methylellagic acid 4′-β-d-glucopyranoside (6), tormentic acid (7), ursolic acid (8), euscaphic acid (9), and betulinic acid (10), was isolated from the twigs of Euscaphis konishii Hayata. Compounds 1, 3, and 5 to 7 were isolated from this plant for the first time, and compounds 1 and 5 were obtained from the plant genus for the first time. The structure of the new compound was confirmed by HRESIMS, NMR, and compared with data from the literature . The cytotoxicities of 10 isolated compounds were tested, with compounds 1 to 6 showing moderately inhibited activity against the Human Hepatocarcinoma cell line (HepG2 cells) with an IC50 value ranging from 69.7 to 181.8 μM.