The homogeneous polyaniline (PAni)/TiO2 nanocomposites were successfully synthesized via a facile emulsion polymerization with the assistance of peroxo-titanium complex (PTC), where PTC was used as both the TiO2 precursor and the oxidant for the polymerization of PAni/TiO2 nanocomposites. Comprehensive analysis indicated that anatase TiO2 nanocrystals (about 4-6 nm) were well-dispersed in the PAni chains without aggregation, and the TiO2 were anchored on the polymer chains through chemical interactions, such as Ti-O-N-C and Ti-O-C, which made the PAni/TiO2 composite possess better thermal stability. The PAni/TiO2 composite could be well dispersed in common solvent, such as acetone, and stay stability without any precipitation for a month. Since the PAni/TiO2 composite could be well dispersed in common solvent, the PAni/TiO2 dispersion may be coated on the surface of Poly (ethylene terephthalate) (PET) film, showing good processable properties, and the prepared PAni/TiO2/PET films exhibit good photocatalysis and best conductivity (2.08 x 10(-2) s cm(-1)), when the molar ratio of aniline (AN) and Ti in the PAni/TiO2 composite is 1/1. The possible reaction mechanism was also discussed. The facile synthesized method proposed can also be used for the preparation of other conducting polymer/semiconductor nanocomposites. (C) 2013 Elsevier B. V. All rights reserved.