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Seismic separators with sufficient initial rigidity will resist the separating structure against lateral loads such as wind or mild earthquakes. Equipping the structure with the Seismic Separation System would result in the centralization of earthquake-induced displacement in the system, as well as a lack of influence on the horizontal component of the Earth's motion. In this research, the modeling of lead-coated rubber separators is compared with the SAP2000 software in two modular steel frame systems and X-axis steel bracing system. Using nonlinear static analyzes, their performance has been evaluated in structures 5 and 10 of the class. The results showed that the average steel moment frame systems with LRB have more energy than concentrically brace frame.