Abstract: Based on the most updated and authorized thermodynamic data, the reactions between SiC and Al₂O₃ have be studied using the equilibrium theory of chemical reactions. The partial pressure of each gaseous product of the reactions is quantitatively analyzed by taking into accounts the carbon activity in SiC and unit and reduced activities of solid reaction products. The chemical stability of SiC-Al₂O₃ interface under an inert ambient of 1 atmosphere has been judged. The criterion used in the judgement is that the total pressure of all gaseous products is over 1 atmosphere. The quantitative results are provided as reliable references for materials research.