Effect of seven typical foreign ions in different combinations on hydration reactivity of alite was studied by thermoluminescence(TL), isothermal calorimetry and Fourier transform infrared spectroscopy(FTIR). Results show that the initial hydration reactivity of alite is markedly improved due to the presence of various defects, among which shallow level defects play a more important role than deep level defects. Heterovalent ion replacement has obvious influence on thermoluminescene due to the formation of complex extrinsic defects which result in great changes in the defect energy level distribution of alite. It is demonstrated that the intensity of the original thermoluminescene(metastable energy stored in alite) is affected primarily by the polymorphic form of alite, and then affected by foreign ions, especially heterovalent ions. The positive correlation between the hydration reactivity and the original thermoluminescene only applies to alite with the same polymorphic form.