Abstract: A formulation of itraconazole polymeric micelles was prepared using mPEG-PLA as the drug carrier.mPEG-PLA was synthesized by ring opening and polymerization reaction.ITZ-PM was prepared by solvent evaporation-film dispersion method.The drug-loading and entrapment efficiency were characterized by HPLC.The physico-chemical properties of ITZ-PM was characterized by dynamic light scattering (DLS),atomic force microscopy (AFM) and differential scanning calorimeter (DSC),respectively.The dialysis method was applied to investigate the release behavior of ITZ-PM in vitro,and the release mechanism was further discussed.Drug-loading and encapsulation efficiency of ITZ-PM were 3.82% and 99.4%,respectively；nanoparticle size was 37.8 nm,and pH was 4.48.Itraconazole was found to be encapsulated in the micelles rather than forming a physical mixture by DSC；ITZ-PM exhibited to be almost spherical in shape from the observation by AFM.It was proved that ITZ-PM had sustained-release effect in vitro which could be described by Peppas-Sahlin equation.Results showed that mPEG-PLA can obviously improve the solubility of itraconazole.