Utilization of fuse in concentrically steel braced frame to cope with seismic loads and raising ductility and its impact on the base shear variations is studied in this research. In cbf frames, connections made to cope with lateral loads and to satisfy criteria codes need to be retrofitted , but in the structures with fuse system there is no need to retrofit connections. In this study, two type of fuses are used. The first fuse is created by reducing the cross-section of tubox bracing in certain areas. This type of fuse has been used in the frames of 3&7 story buildings with various openings. The second fuse is created by reducing the cross-section of angles in X bracing steel frames of  2 - 9 story buildings. Therefore, Fuses are designed such that the tensile capacity of bracing is lower than the capacity of connection. To evaluate the performance of the system , tubox sections are placed as diagonal bracing in a frame with 3 meter story height and 4 meter length for its openings. In the second case an angle with 64*64*13 mm section size was considered as X braced in the frames with 2 - 9 story buildings with 1.75 meter story height. Performance of the frames were examined under lateral loads. The above tasks were simulated using Etabs & Abaqus softwares. Results show that the braced frame with fuses well dissipate applied energy to structures from seismic loads. Fuses increase ductility of structure. The formation of plastic hinges on the fuses prevent yielding of connections without the need for retrofitting. Transitional forces to main structural members and base shear of structures is decreased with good performance of fuses, which is an indication of optimal performance of the system and its preference.