Objective: Based on natural biodegradable chitosan,we connected arginine to the 6-amino-acid-position of chitosan in order to made the arginine modified chitosan.Then we obtained the derivative polymer by coupling decanoate.Use the derivative polymer to assembled into capric acid grafted arginine modified chitosan.Then prepare arginine-chitosan-decanoic acid polymer micelles(Arg-CS-DA) (Fig.1,Fig.2) and use it as a carrier to encapsulate harmine(HM).HM-Arg-CS-DA can enhance the antitumor activity of HM and reduce its toxic side effects.Method: Use IR,1H NMR ,wide angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC) to analyze its physical properties.Examine its solubility in various solvents and its solubilization ability of insoluble drugs.Examine the cytotoxicity of drug-loaded micelles by MTT.Use transmission electron microscopy morphology for observation of micelles, and dynamic light scattering method for the determination of particle size and size distribution.In addition, we adopted UV method for determination of entrapment efficiency, drug loading and release rate in vitro, determination of toxicity of HM-Arg-CS-DA micelles and free HM on HepG2 cell by MTT assay.Results: The molecular weight of amphiphilic block copolymer arginine-chitosan-decanoic acid (ARG-CS-DA) from the experiment is about 9.1 kD.The critical micelle concentration of OACS was 3.299× 10-2 mg.mL-1 tested by fluorescence spectrometry.The solubility test shows that ARG-CS-DA could easily dissolve in pH 1-12 solutions and self-assemble to form a micelle solution with light blue opalescence in water.The ARG-CS-DA micelles have a mean size of 166.3nm (Fig.3), polydisperse index of 0.2 and a ζ potential of +21.75 ~+29.80 mV determined by malvern zetasizer.Thus, ARG-CS-DA micelles were a promising nano vehicle with permeation enhancement and drug carrier capability.(2) Using density gradient centrifugation can be separated from the high purity LDL.LDL Succeed to connect micelles.(3) Transmission negative staining photos from electron microscopy shows that HM-Arg-CS-DA micelles are spherical, more uniform size, smooth edge and narrow particle size distribution and uniform, the average particle size of 240nm, and HM can be loaded Arg-CS-DA micelles.In vitro release test results show that HM-Arg-CS-DA micelles are stable in PBS (pH5.3, pH 7.4), and which accord with Weibull release model.In vitro release toxicity test showed that HM-Arg-CS-DA micelles could significantly improve the inhibition effect of HM on the growth of HepG2 cells.Animal experiments show that the safety evaluation, the degree of hemolysis of drug-loaded micelles was significantly lower than that of flee drugs.(Fig.4)Conclusion: The HM-Arg-CS-DA micelles have good stability and high encapsulation efficiency, and enhance the antitumor activity of HM significantly.Arg-CS-DA is a kind of desirable efficient delivery carrier for HM.