Abstract: Effects of calcium compounds on the carbothermic reduction of vanadium titanomagnetite concentrate (VTC) were investigated. It was found that calcium compounds had great effects on the metallization rate of the reduction product, the order of the metallization rate of reduction product being CaCO₃ > no additive > CaSO₄ > CaCl₂, which indicated that the addition of CaCO₃ was more conducive to promoting the reduction of iron than other calcium compounds. Gas analysis showed that there were mainly two processes in the carbothermic reduction of VTC, a solid–solid and a solid–gas reaction. The concentrations of CO and CO₂ were highest when CaCO₃ was added, while that in a roasting system decreased the most when CaCl₂ was added. X-ray diffraction (XRD) analysis showed that calcium compounds could change the reduction process of ilmenite in VTC. The phase compositions of the reduction products were changed from metallic iron (Fe) and anosovite (FeTi₂O₅) to metallic iron (Fe) and perovekite (CaTiO₃) when calcium compounds were added. Additionally, CaSO₄ and CaCl₂ could significantly promote the growth of metallic iron particles, though the existence of Fe-bearing Mg₂TiO₄ in reduction products was not conducive to the reduction of iron. The formation of FeS would further hinder the reduction of iron after adding CaSO₄.