The extinction spectra and electric field distribution of silver nanosphere arrays positioned in a line, plane or cube are calculated by discrete dipole approximation. It is demonstrated that the surface plasmon resonance peaks of extinction spectra are red-shifted with the increase of silver nanosphere diameter and blue-shifted with the increase of the number of nanospheres. The coupling effects of silver nanoparticles with different structures between arrays have a significant impact on their surface plasmon resonance mode. It is found that the electric field coupling effects of silver nanosphere arrays positioned in a plane, cube and line is weakened in the order, when the arrays have the same diameter. The spectral characteristics of nanosphere arrays are closely related to the changes of polarization state of the incident light.