The gigaporous microspheres based on a copolymer of glycidyl methacrylate and ethylene dimethacrylate were prepared by atom transfer radical polymerization(ATRP). The microspheres were characterized by Fourier transform infrared spectrometer, scanning electronic microscopy and mercury intrusion porosimetry. The results indicated that the microspheres by ATRP showed larger size pore and surface than those by conventional free radical polymerization (CFRP). It was observed from the morphology of the microspheres that the smaller size of particles (100-400 nm) formed the skeleton of microspheres by ATRP than CFRP method (1000 nm). Meanwhile the size of these particles by ATRP was well-distributed in comparison with CFRP. These microspheres by ATRP showed good potential in rapid separation of proteins.