Abstract: As the scatterer's size is no less than or comparable with the wavelength, a rigorous solution of multiple scattering Maxwell's equation must be used. Multiple scattering formulation of T-matrix method is adopted to develop numerical simulations of polarized scattering from clustered spherical particles. Numerical results for coherent scattering from non uniformly clustered scatterers are presented. Numerical calculations are also well compared with experimental data of a two-sphere cluster.