Novel polyvinyl chloride (PVC) membrane electrodes containing triheptyl dodecyl ammonium iodide as electroactive materials exhibit excellent potentiometric response to the complex of hydrogen peroxide and hexavalent molybdenum. A potentiometric glucose biosensor was developed based on the PVC film electrode which was employed as a platform to immobilize Glucose oxidase (GOD). Under the optimization experiment conditions, experimental results show that the biosensor responds linearly to glucose in the range from 2×10^－4 to 5×10^－3 mol/L, the detection limit was 5×10^－5 mol/L. In addition, the biosensor exhibits high stability and good selectivity against common interfering species such as ascorbic acid, uric acid and some kinds of amino acids.