The mechanical properties of nanoporous Au (NPG) thin films were investigated by uniaxial microtensile tests. Such mechanical parameters as Young's modulus, tensile strength, and breaking strain were obtained from the recorded force-displacement curves. Through observations on the microstructure and fracture surface morphology of the samples after the tension tests by a scanning electronic microscope (SEM) and an optical microscope, we analyzed the physical mechanisms underlying the mechanical behavior of NPG thin films. It was found that the NPG films exhibit mechanical properties distinctly different from its bulk counterpart.