A biochemistry nanosensor was put forward on the basis of a new structure: hybrid metallic nanostructure array (spherical and pyramidal-shaped nanoparticles) in this paper. The hybrid metallic nanostructure array consists of two types of Ag nanostructures: spherical and pyramidal structures patterned with the same period. Design, fabrication and characterization of the Ag nanostructures were presented. Relevant experimental results were obtained by means of detecting the transmittance spectra of the hybrid metallic nanostructure. Apparent shifting of peak wavelength of the transmittance spectra occurs while varies the periods and the effective refractive index of surrounding mediums. Moreover, there are some sharp and narrow peaks of the transmittance spectra by which it can improve the resolving power of the biochemistry nanosensor. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.