Abstract: Inclusions before and after ESR process were compared and the influence of two slag systems and oxygen content in consumable ingots were analyzed. The results show that different slag systems will affect the result of inclusions removal, higher w（CaO）/ w（Al₂O₃） will reduce the level of inclusion and total oxygen content. In ESR process, the sort and chemical composition of inclusion have no difference with different oxygen content in consumable ingots（in inclusions w(MnO)/w(MnO+Al₂O₃)≈0.23~0.32）, which means oxygen content in consumable ingots have no direct relationship with cleanness of ESR ingots. Using consumable ingots, whose oxygen contents diverse from 40×10^-6 to 100×10^-6, both total oxygen contents after ESR are（20~30）×10^-6.

Key words: inclusion, slag system, total oxygen content, cleanliness