A new polyvinyl choloride (PVC) membrane sensor for cerium (III) was prepared based on 4,13-didecyl-1,7,10,16-tetraoxa-4,13-diazacyclooctadecane (kryptofix22DD) as an ionophore. The sensor exhibites a linear concentration range of 1.0×10-6 to 1.0×10-1 M, with a Nernstian slope of 18.0±1.0 mV/decade, and a detection limit of 9.7×10-7 M. It has a fast response time (5 s) and can be used for two months without any considerable divergence in its potential. The proposed sensor revealed high selectivity toward Ce3+ ion with respect to some alkali, alkaline earth and transition metal cations. It could be used in a wide pH range of 2.0-11.0. The sensor was successfully used as an indicator electrode in potentiometric titration of Ce3+ ion with ethylenediaminetetraacetic acid (EDTA) and sodium iodide (NaI) solutions, and in determination of Ce (III) concentration in real samples.