In this work, the highly selective and stable mixed potential type stabilized zirconia (YSZ) based gas sensor using Cd₂V₂O₇sensing electrode (SE) synthesized via simple coprecipitation method was fabricated and developed for effective detection of NH₃at 650℃. The as-prepared Cd₂V₂O₇sensing material was characterized by X-ray diffraction (XRD), Raman spectrum, X-ray photoelectron spectroscopy (XPS) and Field-emission scanning electron microscopy (FESEM). The results of gas sensing measurement indicated that the sensor attached with Cd₂V₂O₇-SE displayed the response value of - 68 mV and rapid response rate of 5 s to 100 ppm NH₃at 650℃. The present device also exhibited the low detection limit of 1 ppm and the piecewise sensitivities of -6 and -66 mV/decade to NH₃in the concentration ranges of 1-10 ppm and 10-200 ppm, respectively. Moreover, the fabricated sensor showed good reproducibility, excellent selectivity, stability to oxygen concentration, relative humidity and 30 days continuous aging of high temperature at 650℃. And the complex impedance and polarization curves were performed to explain the selectivity and verify the sensing mechanism involving mixed potential model.