A new xanthone, 1,7-dihydroxy-2,3,5,6-tetramethoxyxanthone (1), together with eight known compounds including one xanthone (2) and seven isoflavones (3-9) has been isolated from the leaves of Millettia pachyloba. This is the first report on the isolation of xanthone from the genus Millettia. The structure of the compound 1 was elucidated on the basis of spectroscopic data interpretation, including 1D and 2D NMR and HREIMS. Compound 1 exhibited weak cytotoxicity against five human cancer cell lines, HL-60, SMMC-7721, A-549, MCF-7 and SW480.