Abstract: In order to produce low oxygen steel with high quality, converter slag-tapping, slag oxidability and oxygen activity were analyzed. In addition, modifying and adding process of slag, control of slag oxidability and bottom argon-blowing in ladle were researched as well. On this basis, refining process which is good for low oxygen steel producing with converter-continuous casting process has been developed. The results show that w(TO) in steel is not more than 15×10-6.