For the hardness testing at nano-scale, the load-depth curves are obtained by nanoindention testing machine and real 3-demention morphology images of indentation are obtained by atomic force microscopy. The nanoindentation hardness can be achieved by these curves, images and corresponding calculating method. The nanoindentation hardness values are different because of different calculation and measurement methods. Comparing and analyzing these methods, their advantages and disadvantages are presented, and the future tendency of nanoindentation hardness calculation and measurement methods is presented.