Three-dimensional chiral shell-like silver nanostructures are fabricated by micro-sphere self-assembly and tilted vacuum thermal deposition techniques,and the nonlinear saturation absorption characteristics of the sample are investigated by Z-scan technique with 4ns pulsed Nd:YAG laser at 532 nm wavelength.Our results show that when the irradiation intensity reaches to 2.5×109 W/cm2,the derived nonlinear absorption coefficient β can achieve to -1.45×10-5 cm/W,which is four orders of magnitude larger than the nonlinear absorption coefficient -1.5×10-9 cm/W of colloidal silver nanoparticles in suspensions.We also found that the nonlinear absorption coefficient of the silver nanostructure changes significantly with the polarization direction of incident light.The enhancement mechanism and polarization dependence of the nonlinear absorption are analyzed and discussed.