Styrene-maleic　anhydride　copolymer　(SMA)　with　controlled　molecular　weight　(Mn)　and　narrow　dispersity　was　prepared　by　RAFT　polymerization.　The　effect　of　reaction　time　on　monomer　conversion　was　investigated,　and　the　conversion　of　monomer　could　achieve　99.1%　after　24　h　at　the　temperature　of　55　°C.　The　synthesized　SMA　was　characterized　by　Fourier　transform　infrared　spectroscopy　(FTIR),　nuclear　magnetic　resonance　(NMR)　and　size　exclusion　chromatography　(SEC).　The　result　demonstrated　that　the　polymerization　of　SMA　was　well　controlled　and　the　dispersity　()　of　SMA　was　lower　than　1.20.　Furthermore,　SMA　copolymers　with　narrow　dispersity　and　well-regulated　Mn　(denoted　SMA1500,　SMA3000,　SMA5000,　SMA8000,　and　SMA15800,　respectively)　were　obtained　by　adjusting　the　molar　ratio　of　monomer　to　the　chain　transfer　agent.　Moreover,　the　synthesized　SMA　was　hydrolyzed　in　NaOH　aqueous　solution.　Then　the　dispersion　of　TiO2　in　aqueous　solution　by　the　hydrolyzed　SMA　and　SZ40005　(the　industrial　product)　were　studied.　The　agglomerate　size,　the　viscosity　and　the　fluidity　of　TiO2　slurry　were　tested.　The　results　show　that　the　performance　of　dispersity　for　TiO2　in　water　by　SMA　prepared　via　RAFT　was　better　than　that　of　SZ40005.　It　was　found　that　the　viscosity　of　the　TiO2　slurry　dispersed　by　SMA5000　was　the　lowest　among　the　SMA　copolymers　tested,　and　the　viscosity　value　of　the　TiO2　slurry　with　a　pigment　loading　of　75%　was　only　76.6　cp.　©　2023　The　Royal　Society　of　Chemistry.