Abstract: Here is analyzed the infuencing factors on properties of platinum electrode in the process of preparation and sintering of the platinum electrode. The response characteristics of oxygen sensor are discussed by the oxygen sensor tension waveform signal from automobile oscilloscope. The results show that the pore-forming agent and sintering temperature of the electrode have a remarkable effect on the microstructure of the electrode. When the Pt/pore-forming agent is in optimum proportion and the ideal sintering temperature is applied, the resistance of the electrode is the lowest. The high potential transition is above 800 m V, the low potential transition is under 100 m V and the time of potential transition is less than 200 ms, which can satisfy the operating requirement of oxygen sensor.