Abstract: OBJECTIVE To synthesis a series of low molecular weight galactosylated fatty acyl chitosan as novel polymeric micellar materials for hepatocyte-targeting, and characterize their structures and properties of polymeric micelles. METHODS Using methanesulfonic acid as reaction medium, fatty acyl chitosans (F-CTS) with different chain length and degree of substitution (DS) of fatty acyl group were synthesized by the reactions between hydroxyl groups of chitosan and fatty acyl chloride (palmitoyl chloride and lauroyl chloride). Galactosylated fatty acyl chitosans (GF-CTS) were synthesized by reactions of lactobionic acid and 2-amino of F-CTS under the activation of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC·HCl). The structure and DS were confirmed by IR and 1H-NMR. The critical micellar concentration (CMC) of F-CTS and GF-CTS were determined, and the particle sizes of polymeric micelles formed were measured. RESULTS F-CTS was synthesized by reaction of chitosan and chloride at 20 ℃ for 1 hour. Then GF-CTS was synthesized by reaction of lactobionic acid and F-CTS at 30 ℃ for 24 hours. The appropriate molar ratio of palmitoyl chloride (or lauroyl chloride) to chitosan was in the range of 2∶1-8∶1 (or 2∶1-10∶1). DS of fatty acyl group ranged from 0.28 mol to 1.13 mol. GF-CTS and F-CTS were soluble in DMSO. The CMC and particle size of polymeric micelles formed were about 0.39×10^-2-2.82×10^-2 mg·mL^-1 and 119.8-546.0 nm, respectively. CONCLUSION Galactosylated fatty acyl chitosans (GF-CTS) are successfully synthesized. The DS of fatty acyl group and micellar properties changed regularly with the aliphatic chain length and molar ratio of chloride to chitosan. With the increase of molar ratio, the DS of fatty acyl group increased, but the CMC and micelle size decreased. With same molar ratio, the micelle size of F-CTS is bigger than that of GF-CTS.