A set of amphiphilic poly(ethylene glycol)-b-poly(ethylene brassylate)(PEG-b-PEB) copolymers based on the PEB hydrophobic block was first synthesized by ring-opening polymerization of ethylene brassylate with an organic catalyst. The EB/PEG molar ratios and reaction times were adjusted to achieve different chain lengths of PEB. Block copolymers that were characterized by1 H NMR and GPC could selfassemble into multimorphological aggregates in aqueous solution, which were characterized by DLS and TEM. The hydrophobic doxorubicin(DOX) was chosen as a drug model and successfully encapsulated into the nanoparticles. The release kinetics of DOX were investigated. A set of amphiphilic poly (ethylene glycol) -b-poly (ethylene brassylate) (PEG-b-PEB) copolymers based on the PEB hydrophobic block was first synthesized by ring-opening polymerization of ethylene brassylate with an organic catalyst. The EB / PEG copolymer ratios and reaction times were were adjusted to achieve different chain lengths of PEB. Block copolymers that were characterized by1H NMR and GPC could selfassemble into multimorphological aggregates in aqueous solution, which were characterized by DLS and TEM. The hydrophobic doxorubicin (DOX) was chosen as a drug model and successfully encapsulated into the nanoparticles. The release kinetics of DOX were investigated.