A new type of designed copolymers has been synthesized for the formation of porous polymeric microspheres. The copolymers contain hydrophobic (styrene, methyl methacrylate, vinylbenzyl chloride, or vinylbenzyl ethyl ether) and hydrophilic (vinylbenzyl alcohol) repeating units. Since the specially designed copolymers have unique chemical and physical properties, the porous structure can be easily accomplished by a facile single-step process. The resulting porous microspheres exhibit good morphological quality, showing open pore structure with a pore size ranging from submicrometer to micrometer, by neither use of porogens nor the requirement of complicated multistep emulsifications. The discovery for the exceptional performance of pores in microspheres is exciting and groundbreaking. The chemical features of the proposed copolymers for the availability in the formation of porous architecture provide important insights into the design principle of high quality porous structures.