Abstract: In this study，MFM is used to scan and observe the surface and magnetization of FePt nanowires scattered

on a SiO2 substrate and their magnetic images are also obtained. The magnetizaion distribution of FePt nanowires

is analyzed based on bright and dark regions shown on magnetic images. The aggregation of nanowires with opposite

magnetization indicates magnetic materials always tend to be in the lowest energy state. The orientation of magnetization

of FePt nanowires can be controlled and magnetic reversal is observed by applying external magnetic field.

Key words: atomic force microscope, magnetic force microscope, FePt nanowires, magnetic reversal