The catalytic photodegradation of Rhodamine B with UV irradiation over NaMO3 (M= Ta and Nb) doped with Y2O3, La2O3, Nd2O3 and Sm2O3 has been studied in our laboratories. All catalysts were characterized by different techniques such as X-ray powder diffraction (XRD) and thermal analysis (DTA/TGA). Surface characterization of the solids was carried out from adsorption isotherms and infrared spectroscopy (FTIR). The band gap energy (Eg) of materials ranged from 4.1 to 2.9 eV. For comparative purpose the materials studied as catalysts were also synthesized by classical solid state reaction.