We improve the resolution and accuracy of ground-penetrating radar (GPR) forward modeling by applying the mesh-less algorithm element-free method (EFM), which is widely used in the electromagnetic field for numerical simulation. EFM dispenses with the concepts of elements, needs only a mass of node information, and adopts the moving least squares (MLS) method to structure a shape function. Advantages of EFM are simple preprocessing, high accuracy, and high successively independent variable solutions. We start with the GPR wave equation, and then discuss the EFM approach and how to combine an improved Sarma absorbing boundary with EFM for GPR forward modeling. We simulate two 2-D models with typical electrical properties. The results show that EFM can calculate stable geo-electric GPR models because the improved Sarma absorbing boundary can absorb incident GPR waves near the model boundary effectively.