Abstarct: These days various systems have been used in contrast with lateral forces, but the earthquake effects are still one of the biggest problems in structure designing in earthquake-prone areas. Typical bracing experiences high lateral deformation due to lateral loads. If this deformation exceeds to a certain extend causes structural and non-structural failure and compromised the safty and integrity of the structure. To overcome these problems a new unbuckling bracing method developed 30 years earlier in Japan. These braces are designed in a way that resisting against buckling and having symmetrical cyclic tensile-compressive cruves due to lateral loads, and optimize the structural behavior in terms of stability and energy absorbing. These day composites are used widely in structures as new materials. FRPs, in addition to being light, improve structure oscillating characteristics. At the present thesis FRP made buckling restrain brace has been examined. The results show that by increasing the steel core cross section area and shape, the cross instead of rectangular, oscillating characteristics have been improved. Furthermore, using triangular cross sections and decreasing the dimensions of the rectangular cross section, the FRP oscillating characteristics have been improved. Also using CFRP instead of GFRP heightens in structure energy absorbing characteristics. For addition, decreasing the cross section dimensions has been examined and results shows no changes in oscillation characteristics.