Monodisperse　copolymer　microspheres　were　prepared　by　dispersion　polymerization　in　ethanel/water　medium　using　polyvinylpyrrolidone　(PVP)　as　a　steric　stabilizer,　2-(methacryloyl)ethyltrimethy　lammonium　chloride　(　MTC)　as　copolymer　monomer　and　2,　2-azobisizobutyronitrile　(AIBN)　as　an　initiator.　The　results　show　that　the　copolymer　structure　synthesized　was　in　accordance　with　the　expectable　structure.　The　influencing　factors　on　the　copolystyrene　microspheres　size　and　size　distribution　were　investigated.　The　amount　of　initiator　(AIBN)　and　stability　(PVP)　influence　the　size　and　the　distribution　of　copolymer　microspheres.　The　amount　of　copolymer　monomer　(MTC)　has　little　influence　on　the　distribution　of　copolymer　microspheres,　but　it　is　in　favor　of　TiO2　coating.