Monodisperse poly(divinylbenzene-co-acrylonitrile) (poly(DVB-co-AN)) microspheres with active cyano groups on the surface and particle size in the range of 0.45～1.79 μm were prepared by distillation-precipitation polymerization in neat acetonitrile in the absence of any stabilizer or additive without stirring and with benzoylperoxide (BPO) as initiator.The comonomer feed ratio has much effect on the morphology and the size of the resultant polymer particles.The SEM images indicated that the copolymer microspheres have spherical shape with smooth surfaces in monodispersity with AN fraction in comonomer feed from 0 to 0.60.The results demonstrated that more functional cyano groups were successfully incorporated into the outer solvent-swollen gel layer of the resultant polymer microspheres with increase AN fraction in comonomer feed.The distillation of a portion of the solvent out of the reaction system during the polymerization was a key problem to avoid the coagulation and afford monodisperse polymer microspheres for the distillation precipitation copolymerization of DVB and AN in acetonitrile.