Objectives Europium ions doped phosphors have been used in a wide variety field. The red light emission of Eu³⁺ is centered near 612 nm, which owing to intra-4f transition. While the emission from Eu²⁺ originating from the dipole allowed 5d-4f transition, varies in a wide range from red to ultraviolet which depending on the crystal structure of host materials. Recently, Sr₂SiO₄ has attracted great interest due to its special structure features and excellent physical and chemical stability. The aim of this paper is to investigate the luminescent behaviors of Sr₂SiO₄:Eu³⁺ and Sr₂SiO₄:Eu²⁺ phosphors. Results show that dual behavior of Sr₂SiO₄:Eu³⁺ and Sr₂SiO₄:Eu²⁺ phosphors may play a positive role in practical applications. Methods: Sr₂SiO₄:Eu³⁺ phosphors were prepared by a conventional solid-state reaction method and Sr₂SiO₄:Eu²⁺ phosphors were prepared by annealing Sr₂SiO₄:Eu³⁺ phosphors at 1100 ?C in a reduction atmosphere. The crystalline structures of the prepared phosphors were investigated by X-ray diffraction (XRD). The luminescent properties of phosphors were investigated by excitation, emission spectra and Commission International del?ˉEclairange (CIE) chromaticity coordination. Results: 1. From XRD patterns, Sr₂SiO₄:Eu³⁺ and Sr₂SiO₄:Eu²⁺ phosphors are the mixtures of the orthorhombic |aˉ-Sr₂SiO₄ with the space group of Pnma and monoclinic |-Sr₂SiO₄ with the space group of P21/n. |aˉ-Sr₂SiO₄ is the major phase of Sr₂SiO₄:Eu³⁺ phosphors, while for Sr₂SiO₄:Eu²⁺ phosphors, the proportion of the two phases are almost equal. Further works are in process to improve the purity of the obtained samples. 2. In the structure of |aˉ-Sr₂SiO₄ and |-Sr₂SiO₄, Sr²⁺ ions locate at two kinds of unequivalent lattice sites, and their coordination numbers are 9 and 10, respectively. When the Eu³⁺ and Eu²⁺ ions are introduced into the Sr2SiO4 matrix, they take the place of the Sr2+. 3. The excitation spectrum of Sr₂SiO₄:Eu³⁺ consists of an intense broad band with maximum at 239 nm and some sharp weak lines in the range from 318 nm to 464 nm. The broad band is related to the O²--Eu³⁺ charge transfer band (CTB). Such result shows that the phosphor can be excited efficiently by low-pressure mercury lamp. 4. The emission spectrum of Sr₂SiO₄:Eu³⁺ shows the typical emissions of Eu³⁺ ions, and the emission peaks can be assigned to the ₅D⁰, _1-7F^J (J=0,1, 2, 3, 4) transitions. The main peak located at 613 nm corresponds to 5D0??2 transition. 5. The excitation spectrum of Sr₂SiO₄:Eu²⁺ exhibits a broad band ranges from approximately 300 to 400 nm with a peak maximum at 370 nm. The strong absorption at 370 nm is attributed to the transitions from the ₄f⁷(₈S^7/2) ground state to the 4f65d1 excited state of the Eu²⁺ ions. The broadness of the excitation spectrum means that the phosphors can be well excited by near-ultraviolet light from 360-380 nm, matches well with the emission bands of the near-UV LED chips. 6. The emission spectrum of Sr₂SiO₄:Eu²⁺ phosphors shows two intense broad emission bands peaked at 470 and 547 nm. The broad emission band is ascribed to a strong coupling interaction between the Eu²⁺ ions and the Sr₂SiO₄ host matrix. 7. The CIE chromaticity coordination of Sr₂SiO₄:Eu²⁺ phosphors under an excitation of 370 nm is (x=0.30, y=0.40). The color temperature calculated from emission spectrum is T_c=6500 K. These two features make Sr₂SiO₄:Eu²⁺ phosphors have great potential application as candidate phosphors for white LEDs pumped by a near-UV chip and our method is a good method to elaborate Sr₂SiO₄:Eu²⁺ phosphors. Conclusion: An effective and simple solid-state reaction technique has been used to prepare Sr₂SiO₄:Eu³⁺ and Sr₂SiO₄:Eu²⁺ phosphors. The XRD pattern show that the phosphors are composed of orthorhombic |aˉ-Sr₂SiO₄ and monoclinic |-Sr₂SiO₄ phase with different concentration. Sr₂SiO₄:Eu³⁺ phosphors show intense emission in the red region when it was excited by 256 nm light. Sr₂SiO₄:Eu²⁺ phosphors give intense white emissions (x=0.30, y=0.40, T_c=6500 K) ranging from 425 to 650 nm when it is excited by near-UV light. The excitation efficiency is very high in the range from 300 nm to 400 nm and centered at 370 nm. The excellent luminescent properties make Sr₂SiO₄:Eu²⁺ suitable for white LEDs phosphors pumped by near-UV chips.