Multi-walled carbon nanotubes (MWCNTs) and titanium dioxide nanocomposites (IVIWCNTs/TiO2) were prepared by a liquid phase deposition method and used as a photocatalyst for degradation of methylene blue (MB) in water under light irradiation. The morphology and microstructure of composites were characterized by SEM, TEM. and XRD. It was found that the photo-degradation rate of MB under UV or visible light irradiation depended strongly on the special structure of supported catalyst, pH and electron acceptor (H2O2 used in this study). Those results showed that the MWCNTs/TiO2 composites may be used to adjust the degradation property and may extend potential applications for degradation of organic pollutants. (C) 2010 Elsevier B.V. All rights reserved.