From the root of Momordica cochinchinensis SPRENG. (Cucurbitaceae), three saponins named momordins I, II and III have been isolated. Their structures were determined on the basis of chemical and spectral evidence as oleanolic acid 3-O-α-L-arabinopyranosyl (1→3)-β-D-glucuronopyranoside (momordin I), 28-O-β-D-glucopyranoside of momordin I (momordin II) and 3β-hydroxy-11α, 12α-epoxy-olean-28, 13-olide 3-O-α-L-arabinopyranosyl (1→3)-β-D-glucuronopyranoside (momordin III). Momordin II was proved to be identical with hemsloside Ma₁ isolated from the tubers of Hemsleya macrosperma and H. chinensis.