A new numerical technique is proposed for computing seismic response of single-degree-of-freedom (SDOF) structural systems to earthquake excitation. It is called Energy-Based Method (EBM) because the main idea of this method is inspired from energy conservation principle. Energy-based method can strongly cope with linear damped systems for which damping ratio ζ is almost greater than 𝟎. 𝟎𝟏. A numerical example is investigated to demonstrate efficiency of the algorithms. The most famous El Centro record is applied to the system which was initially at rest. The obtained result shows that the new algorithm works satisfactorily precise to compete with conventional method of Duhamel integration and Newmark-β method.