One of the challenges in the rare earth elements (REE) production industry is the difficulty of separating them from each other. Therefore, in the present study, the possibility of cerium separation from carbonate Concentrate of REEs containing 22. 75% Ce, 9. 4% La and 8. 6% Nd (total REEs of 41. 51%) was investigated. Two methods were used to separate Ce from other REEs. In the first method, due to the very low solubility of Ce4+, the calcination of carbonate Concentrate and conversion of cerium carbonate to cerium oxide and selective dissolution of other REEs from the calcine were investigated. In the second method, prior to the carbonate precipitation of REEs, the possibility of cerium oxidation in the sulfate solution (by using potassium permanganate) and its subsequent selective separation from other REEs was investigated. Results of the calcination (first method) showed that only 35 and 45% of La and Nd were dissolved at 80 ° C after 2 hours leaching with 1 molar nitric acid, respectively. Results of the calcine leaching with 4 molar nitric acid at 80 ° C for 2 hours showed that more than 90% of the La and Nd were dissolved. In this conditions, 35% of the Ce was also dissolved and the leaching process was not selective. In the second method, using potassium permanganate with a stoichiometric ratio of 1. 5 to 1 for oxidant to Ce, pH 3. 5 for 1 hour, 98% of the Ce and less than 1% of La and Nd were precipitated. The resulting hydroxide was calcined at 850 ° C for 1 h to produce CeO2 and finally a Ce oxide Concentrate was obtained with 99% purity.