A novel carbon paste electrode (CPE) based on 2, 2'- (ethane 1, 2-diylbis (azanylylidene)) bis (ethan-1- yl- 1- ylidene)) diphenol (L) was prepared for selective determination of trace amount of Pb2+ ion. The effects of individual variables such as amounts of L, sodium tetraphenylborate (NaTPB), graphite powder and Nujol as well as their possible interactions were investigated and optimized using central composite design under response surface methodology. Optimum composition of carbon paste was set as 100 mg Nujol and the mass (mg) ratio of 209/4/6 for graphite powder: NaTPB: carrier, respectively. Such composition was found to be led to significant enhancement in the selectivity and sensitivity of the CPE toward Pb2+ ions over a wide concentration range of 3.7×10-7-1.0×10-2 mol L-1 with detection limit of 1.5×10-7 mol L−1 and a Nernstian slope of 30.7 ± 1.56 mV per decade of Pb2+ concentration. Negligible significant change in response was seen over wide pH range of 4.0-6.0 with response time lower than 14 s. The good selectivity of the CPE for Pb2+ ion toward other metal ions was confirmed by the potentiometric selectivity coefficients. Finally, to be practical, these electrodes were accurately and repeatably used for the determination of Pb2+ ions in real water sample.