The CALPHAD thermodynamic databases are very useful to analyze the complex chemical reactions happening in high temperature material process. The FactSage thermodynamic database can be used to calculate complex phase diagrams and equilibrium phases involving refractories in industrial process. In this study, the FactSage thermodynamic database relevant to ZrO2-based refractories was reviewed and the application of the database to understanding the corrosion of continuous casting nozzle refractories in steelmaking was presented.