Hydrogen storage capacity of SinC60 is studied via first-principles theory based on DFT and Canonical Monte Carlo Simulation (CMCS). it is shown that Si atoms strongly prefer D-site rather than other sites and in these structures maximum number of hydrogen molecule onto any Si atom is one. Each Si atom adsorbs one hydrogen molecule in molecular form and with proper binding energies when Si atom is placed in any D-site of C-60. Si atoms enhance remarkably hydrogen storage capability in fullerene. 2008 International Association for Hydrogen Energy. (c) Published by Elsevier Ltd. All rights reserved.