Abstract In this paper CdS nanoparticles has been synthesized by hydrothermal method, TiO2 nanoparticles by sol-gel and TiO2/MWCNT, CdS/TiO2/MWCNT and CdS/MWCNT composites were synthesized in two steps for controlling the size of nanoparticles. The first one has involved the synthesis of CdS and TiO2 nanoparticles then the addition of carbon nano tube to them in the second step. XRD and FTIR analyses were done for structure study and SEM used for nanocomposite morphology investigation. EDAX element analyses confirmed the success of nanocomposite synthesize. Optical properties of MWCNT were enhanced by adding CdS and TiO2 that PL and UV–vis analyses confirm it. These composites Also have good photocatalytic characteristics.