Abstract: To improve the solubility of quercetin(QT), one of flavonoids that can inhibit the proliferation of various types of cancer cells, the novel amphiphilic polymer N-(4-methylimidazole)-hydroxyethyl-chitosan(MHC), synthetized by chemical derivatization from chitosan, was used as the self-assembly micelles of QT. The formed polymer was characterized by ¹H NMR, elemental analysis and pyrene fluorescence spectrometry. The formulation of MHC micelles loading quercetin was optimized through single factor experiment. Then the optimized formulation was obtained as follows: the concentration of MHC was 0. 67% and the ratio of drug and carrier was 1 ∶10. The micelles particle size was(99. 21±1. 71)nm, Zeta potential was +(20. 01±0. 72)mV and drug loading was(5. 42±0. 32)%. The in vitro release curve was investigated and was found to conform to Higuchi equation of Q=0. 1101t^1/2-0. 064. The results of in vivo experiment showed that the mean rentention time and bioavailability of the MHC-QT micelles were 21. 42 h and 57. 49 μg ·h/mL, respectively, compared to 0. 30 h and 2. 50 μg ·h/mL of the free QT solution. These indicated that the MHC micelles could significantly improve the solubility of QT, the drug sustained-release effect and bioavailability, which would used as carrier for the anti-tumor drugs.