Highly cross-linked polymeric nanoparticles were prepared via novel one-step synthesis by copolymerizing ethylene glycol dimethacrylate (EGDMA) and the ionic liquid, 1-vinyl-3-(2-methoxy-2-oxyl ethyl) imidazolium chloride ([VMIm]Cl). The results indicated that nanoparticles with the average size of about 350 nm could be obtained conveniently through the cross-linking copolymerization. The nanoparticles were characterized using scanning electron microscopy, atomic force microscopy, Fourier transform Infrared, thermo gravimetric analysis, element analysis, and X-ray diffraction techniques. Moreover, the cross-linked polymeric nanoparticles were highly active and selective catalysts for the cycloaddition reaction of carbon dioxide to epoxides. The influences of reaction time, reaction temperature, CO 2 pressure, and amount of catalyst on yield of the products were investigated. The results revealed that cyclic carbonates with high yield (98.4%) and selectivity (100%) could be produced on the condition of 0.1 g catalyst, 5 MPa CO 2 , 160 C and 12 h. In addition, the nanocatalysts could be easily recovered by filtration, and reused several times with only slight loss of catalytic activity.