Deposition of tungsten oxide and molybdenum doped tungsten oxide films on glass, indium doped tin oxide coated glass and silicon substrates under different oxygen partial pressures, substrate bias voltages and substrate temperature by employing RF magnetron sputtering technique. The deposited films were systematically characterized by studying the chemical composition, chemical binding configuration, crystallographic structure and surface morphology and optical properties.The electrochromic and electrochemical properties of the pure and Mo doped WO3 films were studied by three electrode cell configuration with platinum as a counter electrode and calomel electrode as a reference electrode and pure and doped WO3 films formed on ITO coated glass as a working electrode. The cyclic voltammetry experiments were performed by varying the potential in the range from +1 to -1 V in the electrolyte solution of 1M Li2SO4 and at a scan rate of 50 mV/s. The colored and bleached states of the films were recorded using the spectrophotometer.