Metal nanomaterials are widely used in semiconductor materials luminescence, solar cells, surface enhanced Raman scattering detection, and photochemistry, etc., because of their unique local surface plasmon resonance (LSPR) characteristics. Owing to its very low absorption loss in a particular band, Ag is considered as an excellent candidate material for LSPR. In this paper, the near-field local enhancement and far-field scattering characteristics of cylindrical Ag nanostructures are systematically simulated and analyzed by finite-difference time-domain method (FDTD). The results show that the size, spacing and substrate refractive index of Ag nanostructures have significant effects on the LSPR. Furthermore, the LSPR properties of Ag nanostructures can be regulated by changing of the structural parameters.