In this project, mesoporous silica nanoparticles with sizes below 100 nm have been synthesized using silica fume as a source of cheap. By using triblock copolymer (EO 20 PO 70 EO 20 ) as a suppressant of grain growth, mono-disperse spherical MCM-48 mesoporous silica nanoparticles (MSN) with cubic Ia3d mesostructure was synthesized based on the modified St?ber method using hexadecyltrimethyl ammonium bromide as structure directing agent in alkaline solution. The effects of stirring rate and molar ratio of EO 20 PO 70 EO 20 which controls parameters of morphology and particles size are investigated by X-ray diffraction, N 2 sorption/desorption and transmission electron microscopy analyses. Results indicated that MCM-48-type M ( 50 nm) was successfully prepared at a low molar ratio of HDTMA to SiO 2 with high stirring rate to facilitate the hydrolysis of TEOS and formation of three dimensional cubic structure.