MRI is a medical machine which constructs images by way of magnet field changing and parameters got from different dimensions. It could accurately show the detailed data of our body on the computer screen. MRI is one of the important inventions at present. In sports science study, there are still many diverse issue and some relative topics which need to be discussed and broken through. Such as: scientific athletes drafting, the changes of the quantity and strength of muscles pre or post training, the diagnostic analyses of sports injury, and the changes of muscles strength in middle aged and senior people. With the help of MRI, we could predictably and optimistically overcome some limits in sports science study in the future.