a b s t r a c tA series of novel inulin derivatives were synthesized via reaction of chloracetyl inulin (CAIL) with aminopyridines, including 2-(2-amino-pyridyl)acetyl inulin chloride (2APAIL), 2-(3-amino-pyridyl)acetyl inulin chloride (3APAIL), 2-(4-amino-pyridyl)acetyl inulin chloride (4APAIL), 2-(2,3-diaminopyridyl)acetyl inulin chloride (2,3DAPAIL), and 2-(3,4-diamino-pyridyl)acetyl inulin (3,4DAPAIL). The antioxidant property of the products and 2-pyridylacetyl inulin chloride (PAIL) against hydroxyl radicals (• OH), superoxide radicals (O 2 • ), and DPPH radicals (DPPH • ) were evaluated in vitro, respectively. Results showed that 4APAIL and 3,4DAPAIL exhibited remarkable improvement on scavenging• OH and DPPH• , which can scavenge the radical of • OH completely at 0.4 mg/mL. Besides, the scavenging activity of 2,3DAPAIL to O 2• was excellent among all of the tested samples, reaching 85% at 1.6 mg/mL. These data indicate that all of the inulin derivatives have better antioxidant activities than inulin, and the scavenging effect indices are affected by the number and position of the amino group on pyridine grafted to the inulin derivatives.