Hydrophobic biodegradable nanoparticles,micelles and nanogels were three kinds of nanocarriers for drug delivery.The problems of these nanocarriers were low drug loading rate,stability,biocompatibility and biodegradability.A novel nanocarrier for drug delivery was reported in this paper.The backbone of the nanoparticle was poly(ethylene glycol) (PEG) chains,α-cyclodextrins (α-CDs) were threaded on the PEG chains to form a necklace like inclusion complex (IC).The nanocarrier was prepared by crosslinking the head to tail within PEG chains under UV irradiation.H NMR,FTIR,XRD were used to characterize the compositions and structure of necklace like IC.The DLS results showed that the size of the nanocarrier was ranged from 60 to 100 nanometers according to the amount of α-CDs threaded on PEG chains.TEM revealed the nanocarrier was supremolecular cyclic ring structure.The functional hydroxyl groups in α-CDs could immobilize drugs such as doxorubicin for controlled release.