Abstract: OBJECTIVE To prepare the drug delivery system of nano metal organic framework MIL-101(Fe)-NH₂ modified by hyaluronan(HA) and evaluate its antitumor activity in vitro. METHODS MIL-101(Fe)-NH₂ was prepared by solvothermal method. HA-modified doxorubicin-loaded DOX@MIL-101(Fe)-NH₂/HA(DMNH) was prepared by physical adsorption. Scanning electron microscopy, X-ray diffraction and nitrogen adsorption desorption method were characterized. In vitro drug release was investigated by dialysis method, and the uptake of HepG2 cells was detected by laser confocal scanning microscopy. RESULTS The morphology of MIL-101(Fe)-NH₂was regular octahedron. The specific surface area and particle size was 1 061.45 m²·g^-1 and 200 nm, respectively. The size of DMNH was uniform and the specific surface area was 205.84 m²·g^-1. The particle size was 300 nm. The optimal drug loading rate of MIL-101(Fe)-NH₂ was 65.3%. According to the drug release curve, the release of doxorubicin from doxorubicin-loaded DOX@MIL-101(Fe)-NH₂ drug delivery system and DMNH showed time and pH dependent pattern. Cell uptake assay showed that DMNH could transport more doxorubicin into HepG2 cells than other groups, and showed higher cytotoxicity at the same concentration. CONCLUSION The as-prepared drug delivery system DMNH exhibit stable structure, high drug loading and releasing efficiency, excellent tumor targeting and pH responsive releasing, and show great promising in targeted delivery of anticancer drugs.