Abstract: Poly2-(methacryloyloxy)ethyl trimethylammonium chloride(PMETACl) with controllable molecular weight was synthesized in a mixture medium of water and DMF by atom transfer radical polymerization(ATRP),using 2-(methacryloyloxy)ethyltrimethylammonium chloride(METAC)as monomer,ethyl α-bromoisobutyrate(EBiB) as initiator,2,2-bipyridyl (bpy) and CuBr₂ as catalyst and ascorbic acid(AC) as reductant.The product was then treated with ion exchange resin,then the obtained polymeric hydroxide was reacted with glycine.After dehydration,a solid sorbent material of poly(amino acid-based ionic liquid)(PMETACGly),capable of CO₂ capture,was obtained.Their chemical structure and physical and chemical properties of these polymers were characterized by Nuclear Magnetic Resonance(¹H-NMR),TG and Size Exclusion Chromatography(SEC).Results showed that PMETACGly sorbent presented a CO₂ absorption capacity high up to 5.20%(mass fraction) at 40 ℃ under atmospheric pressure and CO₂ environment and also demonstrated a recycling ability by temperature swing.