In this paper, based on the reciprocity theorem, the light scattering from a spherical particle above a slightly rough dielectric surface is studied. According to the electric field integral equation of the surface, the recursive solution for the induced current on the slight rough surface is derived using the perturbation expansion of the surface, and the method for computing the interaction field is given. With considering the known scattering matrix of the slightly rough surface and the spherical particle, the analytical solution of the scattering cross section for the composite model is presented, the backscattering cross sections are calculated and discussed in detail.