Abstract: The self deflection process of bright photovoltaic spatial solitons in photovoltaic photorefractive media is investigated by taking into account diffusion effects.By using perturbation techniques,it is found that the center of the optical beam moves on a parabolic trajectory and,moreover,the central spatial frequency component shifts linearly with the propagation distance.Both the spatial deflection and the angular deviation are proportional to the product of two dimensionless quantities which are associated with the diffusion and the photovoltaic process,respectively.The photovoltaic solitons have a similar way to screening solitons in self bending process.