Luminescent poly(vinyl chloride) (PVC) plastics filling with long afterglow phosphor (SrAl2O4: Eu2+, Dy3+) were prepared via melt blending. To improve the dispersion degree of the phosphor particles and endow the compatibility with PVC matrix, SrAl2O4 Eu2+, Dy3+ was first grafted with poly(butyl acrylate)-poly(methyl methacrylate) (core-shell) (designed as PMMA(PBA)) by in situ emulsion polymerization. The properties of polymer/phosphor composite particles were characterized by fourier transform infrared, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The results show that the polymer had grafted onto the phosphor by chemical bond and the grating ratio was about 6.3%. The results for PVC plastics characterized by scanning electron microscopy show that the interfacial adhesion was enhanced with filling the polymer /phosphor composite particles and the compatibility of phosphor with PVC matrix was improved by coating with PMMA(PBA). And the luminescent PVC plastics filled with PMMA(PBA) /phosphor composite particles show improved mechanical properties and higher phosphorescence when the filling content was more than 3 phr compared with the unmodified phosphor. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114: 496-502, 2009