The thermal dehydration of lithium sulfate monohydrate (LSM) exbibits significant induction period (IP) prior to mass-loss process under isothermal conditions. The average rate of IP is well described by conventional Arrhenius-type temperature dependence. The kinetic behavior of IP dramatically changes by the influence of the atmospheric water vapor pressure, p(H₂O). In this study, a universal kinetic description for the induction period under various temperature, T,and p(H₂O) was trialed through formalizing an accommodation function, a(p(H₂O),P eq(T)),on the basis of classical nucleation theory. Characteristic kinetic behavior of the IP process is discussed by reviewing the results of the universal kinetic approach.