EDF is investigating the dynamic behavior of a tower Concentrated Solar Power plant which consists of a heliostat field, a receiver and a boiler. The paper presents a solution to optimize the aiming point for each heliostat. The method is based on a simplified Gaussian model that reproduces the flux distribution for each heliostat, as a function of sun position. This model is calibrated using flux data generated with Tonatiuh, a ray-tracing software. The total power for the heliostat field is computed neglecting the blocking and shading effect by summing up the contributions of the heliostats. A set of aiming points is obtained by different strategies to optimize the distribution of the flux on the receiver resulting from a compromise between flux spillage and flux uniformity.