Abstract: Five different experimental welding fluxes were used in SAW(submerged arc welding) of both positive and negative polarity.Analyses for oxygen content of droplet were carried out using a LECO interstitial analyzer.It was found that oxygen content welded in DCEP was higher than in DCEN,and the trend became obvious when basicity index was enhanced.It was indirectly shown that metallurgical electrochemical reaction occourred at the interface between molten slag and liquid metal in the cathode and anode of welding arc.Further analyses showed that when welded in consistent parametera,oxyanion content of slag was the predominent factor influencing electrochemical oxygen pickup at electrode-tip.