Ca 2 SiO 4 is a phase-change material, and γand β-Ca 2 SiO 4 usually coexist in the sintered product. The overlap of the diffraction data between the two polymorphs makes the relevant phase identification difficult. In this work, the Eu 3+ rear-earth fluorescence probe is introduced in the preparation of Ca 2 SiO 4 , and the obtained result indicates that the introduction of Eu 3+ ions facilitates the increase in the content of β-Ca 2 SiO 4 in the final product. In addition, the differences of the local coordination environments between the two Ca 2 SiO 4 phases obviously influence the crystal-field splittings of Eu 3+ ions, especially in the 5 D 0 → 7 F 0 nondegenerate and 5 D 0 → 7 F 1 magnetic dipole transition regions. On the basis of the excitation from the Eu 3+ −O 2− charge-transfer band, the low-temperature spectral changes are systematically discussed. The transition area ratios of