The ionic conductivity of solid electrolyte may insufficient, and the sensor output signal will deviate from the theoretical one in low temperature. The performance of oxygen sensor with Ag/air reference electrode (RE) and liquid Bi/Bi2O3 RE was tested in low-temperature LBE at 300 degrees - 450 degrees C and the charge transfer reactions impedance at the electrode-electrolyte interface was analyzed by electrochemical impedance analysis (EIS). After steady state condition, both of the sensors performed well and can be used at 300 degrees - 450 degrees C. Bi/Bi2O3 RE has lower impedance than Ag/air RE. Therefore, the response time of the oxygen sensor with Bi/Bi203 RE is faster than the oxygen sensor with Ag/air RE in the low-temperature region. (C) 2017 The Authors. Published by Elsevier Ltd.