Activators regenerated by electron transfer atom transfer radical polymerization (AGET ATRP) were firstly used in suspension polymerization to prepare macroporous microspheres based on a copolymer of glycidyl methacrylate and ethylene glycol dimethacrylate. Compared to conventional radical polymerization (CRP), the microspheres by AGET ATRP showed more homogeneous structure, larger pores, and higher protein binding capacity. The body of microspheres are formed by the large clusters resulted from the aggregated little particles. The size of the particles in microspheres by AGET ATRP was 10-300 nm which was smaller than that (400-800 nm) of the microspheres by CRP. AGET ATRP gave larger pore size (275 ± 5 nm) and surface area (59.3 ± 1 m2/g) than CRP (234 ± 5 nm, 37.5 ± 1 m2/g). The microspheres were modified with polyethylene imine for anion resins that were evaluated in term of its protein binding capacity. The results indicated that the static (69 ± 0.5 mg/mL) and dynamic binding capacity (61 ± 0.5 mg/mL) of proteins on modified microspheres by AGET ATRP were higher than that (34 ± 0.5 mg/mL and 19 ± 0.5 mg/mL) by CRP. Meanwhile, the proteins binding capacity on the microspheres by AGET ATRP decreased only less than 10% when the flow rate increased 10 times. These macroporous media show a large potential in rapid separation of proteins.