Abstract: A solid-contact Pb²⁺-selective-electrodes with polymer-carbon nanotube composites was designed and prepared. In this electrode the methyl methacrylate butyl acrylate copolymer(MMA-BA) was used as the framework of the sensing membrane. The speciality of MMA-BA and polymer-carbon nanotube leads to an excellent reproducibility of the electrode and makes an essential role to enhance the hydrophobicity of the membrane-conductor interface, which contributes to the more stable potential signal by the elimination of undesirable water layer at the interface. The limit of detection in nanomolar range opens the possibility of their use in trace analysis of Pb²⁺ in environmental water samples.