For the purpose of nondestructive determination of the mechanical properties of nano-scale materials including nanowires, nanoparticles, etc., an extended AFM-based materials testing method, the contact resonance force microscopy (CR-FM), is applied. This CR-FM method features high lateral (dimensional) resolution and low test force (down to subnanonewton). It can be employed for not only hard materials, but also soft materials or weak structures, like silicon nano-pillars. In this method, the elastic material properties are deduced by experimental measurement of the resonance frequency shift of an AFM cantilever before and after mechanical contact with the specimen under test. Numerical and analytical investigations of the key issues of this method, including (1) body stiffness of nanopillars, (2) tip-surface mechanical interaction and (3) theoretical measurement resolution, have been carried out, in order to prepare the design and the development of the experimental system. To improve the measurement uncertainty of this method, a MEMSbased cantilever stiffness calibration approach and an interferometric cantilever deflection measurement system have been developed.