Due to the particular tubular molecular structure, carbon nanotubes exhibit various excellent physical and chemical properties and potential application prospect. With constantly developing preparation technology of carbon nanotubes, decoration and application of carbon nanotubes arouse widespread attention. Carbon nanotubes coated with TiO2 and ZnO nanoparticles (TiO2-CNTs and ZnO-CNTs) were performed by sol method and a part of them were irradiated under electron-beam to be decorated further in the present study. All the prepared nanotubes were characterized by TEM, XRD and BET techniques. Methyl orange solution was used as organic wastewater to be photolyzed to evaluate the photocatalytic activities of the TiO2-CNTs and ZnO-CNTs (both non-irradiated and irradiated). Optimum conditions were determined during the photolysis.