Abstract: In order to explore the metallurgical behavior of bottom blowing CO₂ in ladle furnace, CO₂ was used during the LF refining process, some thermodynamics calculation of bottom blowing CO₂ was studied, and some exploratory experiments were conducted with different proportions of CO₂ to Ar during the LF refining process in industry. The results show that it can cause the little oxidation of C in molten steel with the process of bottom blowing CO₂, the average oxidation of C is from 0.3 to 0.8 kg. Compared with bottom blowing Ar, the types and composition of inclusions have less change and the equal yield density of inclusions decreases and the cleanness of steel is improved, it will not aggravate the erosion of ventilated bricks of LF. So it is possible to use CO₂ in LF for refining.