Abstract: The temperature independence law of the effect of third component on the saturated solubility of carbon in Fe-V melt was put forward,and the solubility expression of carbon in Fe-V melt was got with the saturated solubility of carbon of this work and reference data at different temperature, and these thermodynamic property parameters were calculated. At the same time the applied analysis for the transition temperature of vanadium oxidization were carried out and the result approaching the practical production was made.