A new approach was developed to fabricate nanowires of mixed oxides MoO3-V2O5 inside the channels of mesoporous silica SBA-15. The method involves functionalization of the channel surface of SBA-15 with aminosilane groups, immobilization of Keggin-type molybdovanadophosphoric acids through an acid-base interaction, and heat treatment. The immobilization of the heteropolyacid containing mixed addenda makes the molar ratio of the loaded components controllable. The formation of the MoO3-V2O5 nanowires inside the channels was monitored by variable temperature in situ XRD. The materials obtained by heat treatment at 400℃ for 5 h were characterized by TEM, N2-sorption measurements, laser Raman spectra and UV-Vis diffuse reflectance spectra. Further heat treatment of the MoO3-V2O5 nanowires inside the SBA-15 channels at higher temperature (700℃) destroys the framework integrity of SBA-15 by complete sublimation of MoO3 through the SBA-15 channel walls.