A new cucurbitacin glucoside 2-O-beta-D-glucopyranosyl-16alpha-20R-dihydroxy-cucurbita-1,5,23E,25(26)-tetraen-3,11,22-trione (1) has been isolated from the methanolic extract of the fruits of Citrulluscolocynthis. The structure has been assigned on the basis of spectral analysis including 1D and 2D