Mesoporous silica has potential use in catalytic

adsorbent and separate applications. Hybridization with organic groups can improve the surface property of mesoporous silica. In this paper the small angle X-ray scattering technique using synchrotron radiation was used to study fractal structure of mesoporous materials. The results showed that these materials possess both surface fractal and pore fractal structure. Variation of fractal dimension with the material preparation condition was also discussed.