In this study iron oxide was sprayed by the flame and plasma techniques and X-ray diffraction was used to evaluate the possible phase transformation occurred.In this regard morphology and surface composition were studied by Scanning Electron Microscopy (SEM) and FT-IR analysis respectively. The light adsorption ability of the thermally sprayed coatings was also measured by Diffuse Reflectance Spectrometer (DRS) analysis.These studies showed that hematite and magnetite phases were observed in all of the coatings, so changes in flame spraying parameters were done to evaluate the effect of phase transformation on photocatalytic activity. Degradation of Methylene Blue was studied to evaluate the photocalytic activity. The results show the positive effect of thermally sprayed coatings on photocatalytic degradation of Methylene Blue and the sample sprayed at 20 cm spraying distance had the highest efficiency. Rate of the photocatalytic degradation of Methylene Blue was 0.085 hr -1 under visible light irradiation (for F20 sample). The value of band gap determined by Tauc method was 1.7 eV for F20 sample. It was also shown that flame spraying can be more effective than plasma spraying. The results of evaluation the photocatalytic activity also show that pH and the light wavelength are the most effective paramet ers effecting the photocatalytic degradation of Methylene Blue (among concentration, light intensity, light wavelength and pH ). Keywords : Photocatalyst, Iron Oxide, Hematite, Magnetite, Flame Spraying, Plasma Spraying, Methylene Blue.