Mesoporous materials have exceptional properties for application owing to their ability to absorb and interact with guest species. A novel MgO/OMC composite with mesoporous structure was successfully synthesized via in situ magnesiothermic reduction. The structure was confirmed by N-2 sorption isotherms, X-ray diffraction pattern (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). By using nafion and bismuth films as co-modifiers, the MgO/OMC composite material shows high sensitivity of 0.113 mu A.L mu g(-1) and lower background current for electrochemical determination of lead ion (Pb2+) by using anodic stripping voltammetry. The high specific surface area and good mass transfer on the proposed mesoporous material, as well as the outstanding adsorption abilities of MgO to metal ions and the excellent conductivity of the carbon skeleton contribute to the enhanced electrochemical response of Pb2+. As the stripping response of Bi/MgO/OMC-Nafion/PGE is highly linear (R-2 = 0.998) over a Pb2+ concentration range of 2 to 300 mg/L, it was successfully used to analyse Pb2+ in real tap-water samples with good recoveries.