The optical properties of poly(phenylenevinylene) (PPV)/TiO 2 nanocomposites, prepared via the sol–gel process, were investigated by UV–VIS, FT-IR, FL spectroscopy and TEM. TEM images indicated that the surfaces of TiO 2 nanoparticles became rough, and finally formed the connected network as the TiO 2 content increased. FT-IR spectra showed the titanium butoxide hydrolyzed to form Ti organic compound, which can result in the connected network of TiO 2 nanoparticles. The conjugation of PPV polymer chains can be interrupted by the TiO 2 network structure, as evidenced in UV–VIS spectra. The investigation of the PL spectra revealed that the emitted light of the PPV/TiO 2 nanocomposites blue shifted without fine structure, and the PL intensity enhanced, when the TiO 2 network formed. These phenomena suggested that the optical properties of the PPV/TiO 2 nanocomposites were dependent on the interfacial structure between PPV and TiO 2 nanoparticles.