The in vivo behaviors of doxorubicin (DOX)-loaded dextran-poly(3-acrylamidophenylboronic acid) (Dextran- PAPBA) nanoparticles (NPs) were studied. The DOX-loaded NPs had a narrowly distributed diameter of ca. 74 nm and mainly accumulated in liver of tumor-bearing mice after intravenous injection as demonstrated by in vivo real-time near infrared fluorescent imaging. The DOX contents in various tissues were quantified and consisted well with the results of fluorescent imaging. The biodistribution pattern of DOX-loaded NPs encourages us to investigate their liver tumor treatment by using an orthotopically implanted liver tumor model, revealing that the DOX-loaded NPs formulation had better antitumor effect than free DOX.