This paper describes the synthesis and characterization of novel type poly (4-chloromethyl styrene-graft-4-vinylpyridine)/TiO2 nanocomposite. Firstly, poly (4-chloromethyl styrene)/TiO2 nanocomposite was synthesized by in situ free radical polymerizing of 4-chloromethyl styrene monomers in the presence of 3-(trimethoxysilyl) propylmethacrylate (MPS) modified nano-TiO2. Thereafter, 1-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO-OH) was synthesized by the reduction of 2,2,6,6-tetramethyl-1 piperidinyloxy (TEMPO). This functional nitroxyl compound was covalently attached to the poly (4-chloromethyl styrene)/TiO2 with replacement of chlorine atoms in the poly (4-chloromethyl styrene) chains. The controlled graft copolymerization of 4-vinylpyridine was initiated by poly (4-chloromethyl styrene)/TiO2 nanocomposite carrying TEMPO groups as a macroinitiators. The coupling of TEMPO with poly (4-chloromethyl styrene)/TiO2 was verified using H-1 nuclear magnetic resonance (NMR) spectroscopy. The obtained nanocomposites were studied using transmission electron microscopy (TEM), Fourier-transform infrared (FTIR) spectra, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and the optical properties of the nanocomposites were studied using ultraviolet visible (UV-Vis) spectroscopy. (C) 2011 Elsevier Ltd. All rights reserved.