The hypoxia-responsive 6-(2-nitroimidazole) hexanoic acid (NIHA) was synthesized using 2-nitroazole and 6-bromohexanoic acid ethyl ester. The amphiphilic chitosan-g-6-(2-nitroimidazole) hexanamide derivatives (CS-NID) with substitution degrees of 3.9%, 6.3% and 8.9% were obtained by grafting NIHA onto the chitosan macromolecule. The structure of CS-NID conjugates was confirmed by 1H NMR, UV and FT-IR. The micelles were obtained by the self-assembly of CS-NID in aqueous solution and characterized by DLS, Zeta potential and UV. The average size of CS-NID micelles was about 165-190 nm and decreased with increasing the substitution degrees of NIHA. The CS-NID micelles exhibited excellent storage stability, mucoadhesion and hypoxia responsiveness. Doxorubicin (DOX) was encapsulated in micelles by the hydrophobic interaction, and the maximum drug loading content (DLC) and loading efficiency (DLE) of CS-NID micelles were 13.3% and 44.3% respectively. In vitro drug release showed that DOX was released from CS-NID micelles with a distinctly hypoxia-responsive manner. Only 42% of loaded Dox was released from the CS-NID micelles under normoxic conditions over 24h. Notably, about 65% of loaded DOX was released from the CS-NID micelles under hypoxic conditions in 2h, and over 92% DOX was released within 24 h under hypoxic conditions.