Abstract: To study the influence of slag denaturalization process on the top slag oxidation and inclusions in interstitial free (IF) steel, the slag and steel samples were analyzed and taken from different positions in different slag denaturalization experiments.In the results, the best denaturalization effect is obtained by added the denaturalization agent in argon station, the slag oxidizability, indicated as the content of total Fe and MnO by mass in slag, w (T.Fe+MnO) , decreases by 8.73%.Compared with the slag denaturalization process added the denaturalization agent after RH deoxygenation-alloying and RH refining, the number density of inclusions in slag denaturalization process added the denaturalization agent in argon station is decreased by 38.5%and 36.0%, respectively.After RH refining, the number of inclusions in steel is less, but when the slag is in high oxidizability, the oxygen is transferred from slag to steel, which makes the number of inclusions in steel rise.