The algorithm f the sidelobe iev,,i optimization for the dual shaped symmetric reflector antenna with the. aperture diamcier D > 20X is presented. It is based on the method of the far-field paLtern estir.-ion by the aperture distribution. The maximal aperture efficiency is the criterion of t e aperture distribution optimization on the condition that the far-field pattern estimation answers to recommendations ITU-R. Optimization parameters are defined by the function of the aperture distribution that is described as analytical function with shadow area at the center aperture, uniform area and transition regions.