One new cucurbitane-type triterpenoid glycoside, momordicoside X (1), together with five known cucurbitane-type triterpenoids and related glycosides, 3β,7β,25-trihydroxycucurbita-5,23(E)-dien-19-al (2), momordicine I (3), momordicine II (4), 3-hydroxycucurbita-5,24-dien-19-al-7,23-di-O-β-glucopyranoside (5), and kuguaglycoside G (6), were isolated from the whole plant of Momordica charantia. Their structures were determined by chemical and spectroscopic methods. Momordicoside X (1) was evaluated for insulin secretion activity in an in vitro insulin secretion assay and displayed moderate activity.