Abstract: Objective To explore the value of MRI and iron oxide particle labeling in stem cell therapy of stroke model. Methods Nine rats with middle cerebral artery occlusion were randomly selected and underwent Neurological Severity Scoring( NSS), MRI and pathological examination. The results of the 3 evaluation criteria were correlated. Bone marrow stromal cells were labeled with superparamagnetic iron oxide particles. Eighteen models were screened and divided into 3 groups with regards to different transplantation sites. MRI was performed at different time points. The MR appearance of labeled stem cell transplantation sites was observed. The relative infarct volume of the models in the three groups were recorded and compared. Results The correlations among the NSS, MRI and pathological examination were good. Different MR sequences could depict local transplanted labeled stem cells, the gradient echo sequence being the most sensitive method, while the T2WI showed its advantage of better temporal resolution. MR images showed the morphological changes of transplanted stem cells. The change of the relative infarct volume showed no significant differences among the three groups. Conclusion MRI is an ideal tool to evaluate the rat stroke model. MRI together with iron oxide particle labeling technique helps to in vivo track and monitor the transplanted stem cells.