Diisopropyl genistein-7-yl phosphate （C21H23O8P, Mr = 434.11） has been synthesized by a facile phosphorylated reaction with genistein and diisopropyl phosphite, and its structure was determined by IR, NMR, HR MS and X-ray single-crystal diffraction. The crystal belongs to monoclinic, space group P21/n, with a = 9.0690（18）, b = 9.0412（18）, c = 26.544（5）, β = 99.44（3）°, V = 2147.0（7） 3, Z = 4, Dc = 1.344 Mg/m3, μ = 0.172 mm-1, F（000） = 912, the final R = 0.0545 and wR = 0.1352. In the crystal structure, the title compound is constructed by both intramolecular （O-H···O=C） and intermolecular （O-H···O=P） hydrogen bonding as well as π-π stacking interaction.
