Radar Cross Section (RCS) reduction of objects such as airplanes and ships is an important topic for radar and electronic warfare industry. Using the concept of coordinate transformation, one can reduce the RCS by creating a transformation medium around the object. Due to the anisotropic and spatially-varying nature, physical realization of such media is quite difficult. In this study, a new RCS reduction (RCSR) technique is introduced, which provides isotropic and physically-realizable dielectric layers coated over the object. The electrical parameters, such as dielectric constant and loss tangent, of these dielectric layers are obtained by genetic optimization technique, which tries to find the optimal material parameters with respect to the field behavior in transformation media. Using this technique, RCS of the object which is coated by isotropic dielectric layers shows good similarity with the RCS of the anisotropic transformation medium which is designed by using coordinate transformation technique. All simulations in this study are performed by the Finite Element Method (FEM).