Nowadays the research on synthesis of inorganic luminescent material with proper dimensions and morphologies has attracted great attention. Inorganic luminescent materials like LaPO4 have found many practical applications in the field of electroluminescent devices, integrated optics, biological labels, modern lighting and display fields. We have prepared Dysprosium (Dy) doped LaPO4 nanoparticles at relatively low temperature in polyethylene glycol (PEG) medium by wet chemical method. Dy 3+ is doped in LaPO4 at various atomic concentrations (1, 2, 5 and 10 at %). All the samples have been characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), photoluminescence (PL) and thermoluminescence (TL) techniques. XRD study reveals the monoclinic structure of prepared nanoparticles. Unit cell volume is found to be decrease linearly with increasing Dy 3+ concentration indicating homogeneous substitution of La 3+ ions in LaPO4 by Dy 3+ . From the FTIR study it is found that the band at 1044 cm -1 assigned to the phosphate group PO4 3- in the region of υ3 anti-symmetric stretching of P-O band. The PL spectrum shows emission band at about 435 nm is observed due to the transision of Dy 3+ ions corresponding to wavelength in the blue color region. The glow curve of LaPO4: Dy phosphor obeys second order kinetics.