Poly (methyl methacrylate-co-divinylbenzene) [P(MMA-co-DVB)] microspheres were first synthesized by a simple photoinitiated emulsion polymerization methods. In this polymerization system, MMA, DVB, AIBN, isopropanol and hexahydrobenzene constituted the oil phase, SDS acted as the stabilizer and an 8 W Ultraviolet lamp was employed as the light source. Under the irradiation of the UV light, AIBN could be decomposed to produce radicals and initiate the polymerization of MMA to produce P(MMA-co-DVB) microspheres.The morphologies and structures of the products were characterized by Fourier transform infrared spectroscope (FTIR),size distribution, scanning electron microscope (SEM). The average diameters of the spheres increased with the content of DVB. The research may provide a quick, green and facile room-temperature approach to prepare polymer microspheres.