(FePt/Ag)n nano-multilayers were deposited on MgO(100) single crystal with laser ablation and then subjected to annealing. FePt L10 grains with (001) texture and a large perpendicular magnetic anisotropy constant Ku of the order of 106 J/m3 were formed. A thick Ag layer is found to be favorable for improving the (111) preferential orientation and decreasing the dispersion of the easy axis for magnetization. The measurement of time decay of magnetization gave rise to an activation volume as small as 6×10?25 m3, showing the promising perspective of being the recording medium for future high density perpendicular recording.