With the progress of nanotechnology and molecular biology, nanoparticles have been widely studied and applied in biomedicine. Particularly, characterized by unique magnetic property, targeting, and biocompatibility, magnetic nanoparticles have become one of the research hotspots in the nanomedical field. Herein, we summarized the recent advances of magnetic nanoparticles in medicine, including the property, carrier function, MRI, and tumor magnetic inductive hyperthermia of magnetic nanoparticles.