MCM-41 and Al-MCM-41 has been synthesized using cetyl-trimethylammonium bromide (CTAB) surfactant as template and adding the silica precursor to aqueous solutions containing CTAB. The obtained solids were calcined at 600 A degrees C for 4 h. HPW heteropolyacid supported on the mesoporous were prepared using the incipient wetness method. The characterization of materials was performed by X-ray diffraction, Transmission Electron Microscopy, N-2 adsorption, Si-29 Cross Polarization-Magic Angle Spinning and Al-27 MAS NMR. Results showed that the hexagonal structure is obtained in both cases. The Aluminium species are located inside an extra-framework. The impregnation reduces the surface area of the mesoporous materials especially of the Al-MCM-41 suggesting a participation of aluminium during the impregnation. HPW is well dispersed in the mesoporous materials and is located inside the pores interacting with the silanol group of the pores wall. Al-27 MAS NMR measurements have showed that the impregnation causes the removal of the non-framework aluminium.