Abstract: Hyaluronic acid (HA) was used as drug delivery carrier, and the doxorubicin (DOX), IR808 and catalase (CAT) were modified on hyaluronic acid (HA) to form the nano-probe CAT@HA-DOX-IR808 NPs with anti-tumor and fluorescence imaging by self-assembly.It was characterized by UV-Vis spectrophotometer, fluorescence spectrophotometer and transmission electron microscope, and its fluorescence imaging and antitumor activity were studied at solution and cell level.The experimental results showed that CAT@HA-DOX-IR808 NPs displayed a uniform near-spherical morphology with a size of 75 nm approximately.Under the condition of pH 5.0 + hyaluronidase (HAase), the release rate of DOX reached more than 80% in the first 10 hours. In the CD44 positive cells, laser confocal imaging results showed that the group of CAT@HA-DOX-IR808 NPs had more significant fluorescence signals than the group of free drugs and negative cell.In the cytotoxicity test, only about 40% of the MDA-MB-231 cells survived at the highest concentration of CAT@HA-DOX-IR808 NPs of the group of CAT@HA-DOX-IR808 NPs + NIR.Therefore, CAT@HA-DOX-IR808 NPs possess significantly enhanced anti-tumor effect with broad application prospect in the imaging and treatment of breast cancer in vitro.