A selective and sensitive polymeric membrane sensor based on the incorporation of Di-tertbutyl- 1-(tert-butyl thio)-1,2-hydrazine dicarboxylate as a sensing compound in a poly(vinylchloride) (PVC) for the determination of the Lu3+ ions was constructed.. The membrane sensor further comprises nitrobenzene (NB) as a plasticizer, and the role of sodium tetraphenyl borate (NaTPB) as an anionic additives was also evaluated. To investigate the membrane electrode selectivity, its potential response was monitored in the presence of various interfering foreign cations using the matched potential method. The sensor's selectivity against a lot of common alkaline, alkaline earth, transition, heavy metals and specially lanthanide ions was very good. The developed sensor was successfully applied as an indicator electrode in Lu3+ ion potentiometric titration with EDTA. The constructed sensor accuracy was investigated by the monitoring of Lu3+ in mixtures of two and three different ions.