This research studies the selective catalytic reduction (SCR) of nitrogen oxide by ammonia over V2O5-WO3-MoO3/TiO2 catalysts. Titanium dioxide is prepared by a sol-gel method and vanadium, tungsten, and molybdenum are loaded to the prepared TiO2 by impregnation method. Various techniques including BET, XRD, NH3-TPD, FT-IR and ICP-OES are employed to characterize the catalysts. The catalytic activity testing is carried out in a temperature range 100-450°C. V2O5-WO3-MoO3/TiO2 characterized by XRD and FT-IR indicates that the metal oxides on the surface of catalysts possibly form new mix metal oxides. V2O5-WO3-MoO3/TiO2 catalysts characterized by NH3-TPD indicates that the metal oxide are poly layer. V2O5-WO3-MoO3/TiO2 catalysts have behavior between V2O5-WO3/TiO2 at high temperature and V2O5-MoO3/TiO2 at low temperature. 3V7W5Mo/TiO2 catalyst is founded to be a suitable catalyst due to that can maintain high activity in the widest temperature range.