Dispersion copolymerization of styrene with polyethylene glycol 200-dimethacrylae as the cross-linking agent was completed by using poly(N-vinyl pyrrolidone) and 2,2-azo-bisisobutyronitrile as the steric stabilizer and initiator, respectively. Crosslinked copolymeric microspheres were prepared directly by the one-step method of dispersion copolymerization. The effects of the content of polyethylene glycol 200-dimethacrylae on the particle morphology and the copolymerization rate were investigated. It shows that the crosslinking agent plays an important role in the particle morphology and the system stability. When the content of crosslinking reached 2.5wt%, the floriated particles were obtained. Dispersion copolymerization of styrene with polyethylene glycol 200-dimethacrylae as the cross-linking agent was completed by using poly (N-vinyl pyrrolidone) and 2,2-azo-bisisobutyronitrile as the steric stabilizer and initiator, respectively. Crosslinked copolymeric microspheres were prepared directly by the one-step method of dispersion copolymerization. The effects of the content of polyethylene glycol 200-dimethacrylae on the particle morphology and the copolymerization rate were investigated. It shows that the crosslinking agent plays an important role in the particle morphology and the system stability When the content of crosslink reached 2.5 wt%, the floriated particles were obtained.