A phosphor of the Sr₈Al₁₂O₂₄S₂ doped Eu²⁺ (SAOS: Eu²⁺) were prepared by mild hydrothermal method followed by a multi-steps heat treatment process. The as-prepared powders were first annealed at temperature range of 1100 to 1300⁰C in air ambient and then followed by a reducing process in Ar/H₂ to archieve Eu²⁺ - doped phosphors. It has been found that typical phases of SrSO₄, SrAl₂O₄, SrAl₁₂O₁₈ co-exist in the powders annealed below 1200⁰C. The intermediate phases of Sr₄Al₆O₁₂SO₄ is formed at above 1200⁰C, which is subsequently reduced at 900⁰C in reducing ambient to form final phase of Sr₈Al₁₂O₂₄S₂ at second stage. The photoluminescence (PL) emission spectrum shows a yellowish-orange band centered at 612nm, which corresponds to the transition from 4f⁶5d¹ to 4f⁷ of Eu²⁺. No emission peaks of Eu³⁺ are observed, revels that Eu³⁺ is totally reduced to Eu²⁺ in the samples at second stage. The photoluminescence (PL) excitation spectrum show a broad extending band, peaked at 430, 460 and 490nm which matches the emission of blue light-emitting diodes (blue-LEDs). The critical quenching doping concentration of Eu²⁺ in host material is about 5% mol which related to a dipole-dipole interaction. The optical properties of remote White-LEDs devices using various mixed content of YAG: Ce³⁺ and SAOS: Eu²⁺ were measured using integration sphere tester system. The CCT of mixed phosphor plate at the same 25µm phosphor thickness can decrease from cold white light (approximately 6105K, blue-LED+YAG:Ce³⁺) to warm white light (2500-3500K); the optimum CRI of 78 achieved with the mixing content of 20%wt SAOS: Eu²⁺ and 80%wt YAG: Ce³⁺, which is prefer to indoor lighting application.