The electromagnetic inverse scattering problem of determining the locations and polarization tensors of a collection of small scatterers is investigated. The locations of scatterers are determined by the multiple signal classification (MUSIC) method and the polarization tensors are retrieved by the two-step least squares method. Multiple scattering effect is taken into account and the inverse scattering problem is nonlinear. However, the proposed method does not involve iterative evaluations of the corresponding forward scattering problem. In addition, the method provides better imaging resolution than the standard MUSIC does, and applies to degenerate scatterers to which the standard MUSIC does not apply. The underlying mathematical principle and physical insight are discussed in detail.