[SiO(2)](x)[TiO(2)](1-x)(x = 0.1, 0.2, 0.3, 0.4) powders were prepared by hydrothermal reaction of titanium isopropoxide (TIP) and tetraethyl-orthosilicate (TEOS) stabilized in acidic ethanol/water solution. The size and phase of TiO(2) particles were controlled by adjusting the SiO(2) content and the composition of the solvent system. The microstructure and photocatalytic activity of the prepared SiO(2)-TiO(2) nanoparticles were characterized by XRD, TEM, BET, Raman and UV-visible spectroscopic techniques. The major phase for all the prepared samples was anatase. The particle size of 0.3SiO(2-)0.7TiO(2) powders prepared with excess amount of ethanol (R(EtOH) = EtOH/alkoxide molar ratio = 120) was about 8.7 nm, while that of the sample prepared with small amount of ethanol (R(EtOH) = 4) was 9.9 rim. The photocatalytic activity of these composite powders under excess ethanol was 1.5 times higher than that of pure TiO(2) with respect to the decomposition of 1.4-dichlorobenzene (DCB).