In this paper, a new sol-gel method was developed for the construction of CNT-TiO₂ hybrid in which functional MWCNT-COOH, titanium bauxite (TiO₄C1₆H₃₆) and benzyl alcohol (C₇H₈O) was used to produce these nanostructures. The pH of solution was adjusted on 3, 5, 7 and 9. The physical and chemical properties of nanostructured CNT-TiO₂ were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Transmission electron microscopy (TEM) and ultraviolet-visible optical spectroscopy (UV-Vis). The results of the XRD pattern indicate the presence of both the CNT phase and anataze phase of TiO₂ in hybrid products. Microscopic studies also show that in all adjusted pH the hybrid structures with similar mophology were formed. It seems that in basic environment, distibution of TiO₂ nanoparticles positioned on the surface of the MWCNT is more uniform and their sizes are smaller. Photocatalitic property of synthesizd hybrids was investigated by degredation of Methylene Blue(MB) under irradiation of a LED lamp with wavelengh of 397 nm. The results show that i) the photocatalitic activity of hybrid structures are considerably more than pure TiO₂ and ii) the photocatalitic activity of hybrid structures prepared in basic medium is more than acidic one. The most photocatalitic removal of MB was obtained for the hybrid prepared at pH=9.