The effect of ingredient of LF refining slag series (/% : 28. 75 ~ 58. 05CaO

12. 50 〜32. 43A12O3

0 ~ 15BaO

8 ~ 20SiO2

6MgO

10CaFz) on desulphurization of high carbon chromium bearing steel GCrl5 (/% : 0. 99C

1. 45Cr

0. 034S) has been studied by Mo wire high temperature electric resistance furnace and using orthogonal test method. Results shown that as (CaO)/(Al

2

O

3

) = 2. 5 and (SiO

2

)=14%

with increasing ( BaO) from 0 to 8%

the desulphurization rate of liquid by refining slag increases

while with increasing ( BaO) from 8% to 15% the desulphurization rate decreases； as ( BaO) = 7. 5% and SiO2 = 14%

with in

creasing (CaO)/Al

2

O

3

the desulphurization rate by refining slag increases； and as ( BaO) = 7. 5% and ( CaO)/( Al

2

O

3

) =2. 5

with increasing ( SiO

2

)

the desulphurization rate by refining slag decreases. The ingredient of LF refining slag with optimum desulphurization rate of liquid is 6% ~ 10% (BaO)

3.5 -4. 0(CaO)/(Al

2

O

3

) and 8% - 12%SiO

2

.