Photocatalytic degradation of aqueous cyanide was studied. Reaction rate increased as the concentration of dissolved oxygen increased, and reached a saturation when the concentration exceeded 6 ppm. The analysis of the species by ion chromatography along the reaction showed the formation of cyanate as the first photo-oxidation product, and the cyanate eventually began to decompose to other products, mainly nitrate following the complete oxidation of cyanide. Tungsto-phosphoric acid-modified titania (SG-1 and SG-2) showed better activity than the corresponding pure titania (SG-3 and SG-4). Such a trend became obvious when OH·scavengers were added to the reaction system. Preparation methods of the catalysts SG-2 and SG-4 caused smaller particles and higher surface roughness compared with SG-1 and SG-3, respectively.