NiO/mesoporous silica nanocomposite was synthesized through anionic-surfactanttemplated route by using N-hexadecyl ethylenediamine triacetate (HED3A) as structure directing agent. A temperature of 600 • C was chosen to remove the template after an initial thermogravimetric (TG) analysis. Based on the metal sequestration of the template, Ni 2+ was introduced into silica matrix and NiO was finally embedded into mesopores after calcination. The composition of NiO/mesoporous silica composite was qualitatively characterized and quantitatively expressed by Fourier transform infrared (FTIR) spectroscopy, X-ray powder diffraction (XRD) pattern and Energy-dispersive X-ray (EDX) spectroscopy. The composite with high nickel content has a BET surface area reached 676 m 2 g −1 and a pore diameter centered at 3-4 nm. Small-angle X-ray diffraction (SAXRD) pattern indicates that the material possesses ordered two-dimensional (2-D) p6mm hexagonal mesostructure. High resolution transmission electron microscopy (HRTEM) investigation on the structural characteristics confirms the mesostructure and shows that NiO clusters with a uniform size of 15 nm are encapsulated in mesoporous silica.