Abstract: The influence of LF binary refining slag 60CaO-40SiO2 and [O] 27 x 10^-6 as well as ternary refining slag 47.5 - 50. 2CaO-41. 8 ~45. 7SiO2-5 ~8Al₂O₃ and [O] 12 x 10^-6 ~ 14 x 10^-6 kinds, morphology, size and number of inclusions in φ 5. 5mm coil produced by BOF-LF-CC-high speed wire rolling process at steelworks and on wire fracture index during wire drawing have been tested and researched. Results show that with higher oxygen content and binary refining slag, the coil has more inclusions with size more than 7 μm and higher Al₂O₃ content which concentrate near surface of coil within 1 mm depth, and the wire fracture index is 2. 5 ； with lower oxygen content and ternary slag, the coil surface has not larger size inclusions, the size of most inclusions is ~5 μm and the SiO₂ content in inclusions is higher with lower Al₂O₃, and the wire fracture index is 1. 0 ~ 1.5, therefore the performance of cold drawing of steel cord for tyre is markedly improved by using ternary slag containing 5% Al₂O₃ for LF refining and controlling oxygen content in steel- [O] ≤15 x 10^-6 and decreasing number and size of inclusions in steel.