This paper presents the structural and optical properties of europium doped magnesium orthosilicate nanophosphor prepared by combustion method and further annealed at varying temperatures. The structural and optical properties were investigated by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscope (FESEM), High resolution Transmission electron microscope (HRTEM), Diffuse Reflectance Spectra (DRS) and Photoluminescence spectra (PL) together with decay time. The XRD results confirmed the phase formation of Mg2SiO4. FESEM and TEM results indicated spherical particles in nanometer size. Photoluminescence spectra of Mg2SiO4:Eu3+ nanophosphors exhibited five groups of peaks D-5(0) -> F-7(J) (J = 0, 1, 2, 3, 4) transitions. Intensity parameters (Omega(2) Omega(4)) and other radiative properties such as radiative transition probability, total radiative transition probability, radiative life time, branching ratio and stimulated emission cross-section were calculated using Judd-Ofelt theory. The lifetime measurement indicates a decreasing trend up to 5 mol% of Eu3+ concentration. (C) 2016 Elsevier B.V. All rights reserved.