In order to modify inorganic particles as chromatic electrophoretic particles, an approach was designed and used to prepare Fe2O3 red electrophoretic particles. These Fe2O3-cationic hybrid nanoparticles(Fe2O3-CHNPs)were prepared through Fe2O3 core covered with polymer shell which was composed of SiO 2 and P(DMAEMA-co-HMA)by using atom transfer radical polymerization(ATRP)technique. The Si O2-coating could introduce the functional group on the surfaceof inorganic particles, through which the polymer shell could be formed by using ATRP technique. The results of Fourier transform infrared spectra(FT-IR), X-ray photoelectron spectroscopy(XPS)and thermal gravimetric analysis(TGA)confirmed the chemical compositions of Fe2O3-CHNPs; the images of transmission electron microscopy(TEM)indicated the core-shell structure of Fe2O3-CHNPs; the measurements of dynamic light scattering(DLS)showed a 253.7 nm average particle size with narrow size distribution; and the zeta potential measurements identified the high chargeability of Fe2O3-CHNPs. Furthermore, the resulting nanoparticles were successfully applied in the electrophoretic display cell, which demonstrated that it was an effective approach to preparing chromatic electrophoretic particles. In order to modify inorganic particles as chromatic electrophoretic particles, an approach was designed and used to prepare Fe2O3 red electrophoretic particles. These Fe2O3-cationic hybrid nanoparticles (Fe2O3-CHNPs) were prepared through Fe2O3 core covered with polymer shell which was composed of SiO2 and P (DMAEMA-co-HMA) by using atom transfer radical polymerization (ATRP) technique. The Si O2-coating could introduce the functional group on the surface of inorganic particles, through which the polymer shell could be formed by using ATRP technique. results of Fourier transform infrared spectra (FT-IR), X-ray photoelectron spectroscopy (XPS) and thermal gravimetric analysis (TGA) confirmed the chemical compositions of Fe2O3-CHNPs; the images of transmission electron microscopy (TEM) structure of Fe2O3-CHNPs; the measurements of dynamic light scattering (DLS) showed a 253.7 nm average particle size with narrow size distribution; and the zeta potentialimity identif ied the high chargeability of Fe2O3-CHNPs. The resulting nanoparticles were successfully applied in the electrophoretic display cell, which said that it was an effective approach to preparing chromatic electrophoretic particles.