Abstract: Superparamagnetic iron oxide nanoparticles （SPIONs） are a kind of nano materials which have broad application prospects in the field of labeling cells, targeted drug delivery and heat treatment of tumor. Especially in regenerative medicine, more and more research and application of stem cells have been founded. SPIONs have provided a new method to label and track cells. The characteristics of SPIONs are superparamagnetic, low toxicity, good biocompatibility and directional movement in the magnetic field. SPIONs present low signal area in magnetic resonance imaging （MRI） and they can label cells safely and effectively with appropriate coatings. But the uncertainty of cytotoxicity and the limitation of MRI are still unsolved. In this paper, the research progress of SPIONs in labeling cells were reviewed.

Key words: Superparamagnetic iron oxide nanoparticles, Stem cells, Labeling