Abstract: Combining the thermodynamic calculation with industrial production, the variation of inclusions in 304 austenitic stainless steel deoxidized by silicon alloy during LF refining and continuous casting process was investigated. The results showed that the inclusions formed in molten steel are mainly CaO-Al2O3-SiO2 compounds, and the Al content decrease gradually with Si reduction. In the process of LF refining and continuous casting process when the refining slag basicity was controlled at 1.5, the Al2O3 content in the compounds decreases gradually together with CaO and SiO2 contents increasing. The contents of compounds in the final billet are 30%~35% CaO, 20%~27%Al2O3 and 25%~30% SiO2 with other oxides relatively less. The deformability of the billet is relatively low, and the inclusions in it are slightly alkaline.