Abstract: Magnetic resonance imaging（MRI）has a unique advantage in the study of brain functions, but the overlapping of brain tissues and the inhomogeneity of the magnetic fields in the process of imaging, the partial volume effects and noises make the MRI image boundary ambiguous. The image segmentation technology may segment and extract the needed area of medical image and assist the doctor in making an accurate diagnosis. The experimental results show that comparing with other medial segmentation technologies, the fuzzy C-mean（FCM）clustering technology can segment the human brain magnetic resonance imaging effectively. The method to realize the FCM clustering of medical images based on MATLAB is also discussed in the present research.

Key words: FCM clustering, Magnetic Resonance Imaging（MRI）, image segmentation