Abstract: Since the successful synthesis of highly monodispersed iron oxide nanoparticles at the beginning of this century, the biomedical application of these nanoparticles has undergone an explosive growth, becoming the frontier in nanobiology and nanomedicine. In particular, due to their unique properties, magnetic nanoparticles can mediate an external magnetic field and produce physical effects such as induction heat and mechanical force that can further act upon the biotargets on the micro/nano scale. Hence, by using an interdisciplinary approach, novel magnetic nanoparticle based therapeutic modalities that are controllable, safe and accurate are anticipated for disease diagnosis and therapy, so that the therapeutic efficacy and prognosis of diseases can be improved. In this review, the advances in biomedical application of iron oxide nanomaterials in the past five years will be surveyed, and the opportunities and development of these nanomaterials for magnetic resonance imaging, magnetic thermotherapy and biomechanical regulation will be discussed.