A model was proposed and used to calculated the changes in enthalpy (Delta H degrees), entropy (Delta S degrees), and Gibbs energy (Delta G degrees), as well as equilibrium constant (K) relating to the sintering of alumina compacts. Specific nanopore volume (V) of the compacts was assumed as a thermodynamic variable. A hypothetical equilibrium constant (K-h) and corresponding Gibbs energy (Delta G(h)(degrees),) were calculated depending on the V value measured after each sintering. The thermodynamic relationships with the SI units were respectively evaluated for the initial-stage (i) sintering between 1000 and 1200 degrees C and final-stage (f) sintering between 1200 and 1600 degrees C in the following form: AG(i)(degrees) = -RT In K-i - Delta H-i(degrees) - T Delta S-i(degrees) = 161,042 - 110.5T and AG(f)(degrees); = -RTIn K-f = Delta H-f(degrees) T Delta s(f)(degrees) = 39,000 - 47.5T.