Abstract: An Ag/AgCl marine electric field electrode with high porosity was developed by adding a certain amount of sodium bicarbonate(NaHCO₃) foaming agent to the powder pressed Ag/AgCl electrode and utilizing the property that sodium bicarbonate decomposes and produces CO₂ gas in the process of sintering at high temperature.The preparation process parameters of NaHCO₃-Ag/AgCl electrode were studied from the analyzed and measured results of TG/DSC thermal analysis method and weighing method，and a complete set of preparation method of NaHCO₃-Ag/AgCl powder pressed electrode was preliminarily formed. The measured results of electrochemical and detection performances of NaHCO₃-Ag/AgCl electrode show that the exchange current density of the electrode is increased，the range stabiliizing time is significantly reduced，and the self noise is reduced.It shows that the electrochemical and detection performances of the developed electrode are improved compared with those before adding sodium bicarbonate.The preparation method of high porosity marine electric field electrode has good feasibility and application prospect.

Key words: marineelectricfieldelectrode, Ag/AgClelectrode, sodiumbicarbonate, electrochemicalperformance, detectionperformance, highporosity