Nanoporous SiO2 particles which have different pore size and volume were prepared from a colloidal mixture of nano-sized silica particles by a spray heating method. The prepared nanoporous SiO2 particles were employed as a drug carrier to investigate the release behaviors of methylene blue (MB) as a model drug for a selected period of time. The concentration of released MB from the porous particles was measured by a UV-Vis spectroscopy with respect to time. The release of MB from the porous particles was maintained for 400 hours and the maximum amount of the released MB was 0.8 mg at 1.56 cm3/g of pore volume. As pore volume of the nanoporous particles increased, the release rate of MB increased.