TiO2-Ag nanocomposites with well-crystallized TiO2 and randomly distributed metallic Ag nanoparticles were obtained at low temperature (about 50 degrees C) by a modified sol-gel method. The size of TiO2 crystallite was 5-6 nm. With the increasing Ag, Ag particle size increased and the size distribution broadened both due to the agglomeration of Ag crystallites. TiO2-Ag nanocomposites prepared in the present work showed better photocatalytic activity than pure TiO2 prepared under the same conditions. An optimal photocatalyst was obtained when the molar ratio of Ag to Ti was 1:9.