Abstract: To get the composite electromagnetic scattering from the ground rough surface with complex target above, a parametric model of complex targets on the ground rough surface is proposed. Firstly, high-precision 3D geometric modeling of complex targets is carried out, and the model of ground is numerically simulated. With the help of the ray split tracking method, the strong scattering source of the complex environment and the target is decomposed and quantitatively characterized by marking and classifying the spatial ray directly from the established model. Based on the form of attribute scattering center model, the parameters of the scattering center model are determined in the forward direction, the parametric model of the target on the rough surface is constructed. The parametric model of the tank on the bare soil is given, and the synthetic aperture radar (SAR) image reconstructed by the parametric model is compared with the SAR simulated by the high-frequency algorithm. The result agrees well that verified the validity of parametric modeling of the target and the applicable scope of the forward parametric modeling target is expended.