Photo-stimulated desorption (PSD) of Xe from an oxidized Si(0 0 1) surface has been investigated theoretically in connection with a recent experiment by Watanabe and Matsumoto (Faraday Discuss. 117 (2000) 203). We have performed ab initio calculations for the potential energy curves (PECs) of the ground and excited states of Xe/oxidized-Si(0 0 1) and have found that Xe is strongly attracted to the surface in the excited state for a model cluster that takes into account backbond oxidation. The kinetic energy of the desorbed Xe, obtained by classical trajectory calculations using the ab initio PECs, is qualitatively in good agreement with the experimental value.