AbstractRecent earthquakes in Turkey (1999), Taiwan (1999) and Algeria (2003) demonstrated the catastrophic impact of such power upon urban cities. A great number of existing buildings in Algeria designed without seismic design criteria and detailing rules for dissipative structural behavior suffered damages which were far worse than that for newer buildings designed and built according to the more stringent seismic code rules. Thus, it is of critical importance that the structures that need seismic retrofitting are correctly identified, and an optimal retrofitting is conducted in a cost effective fashion. Among the retrofitting techniques available, steel braces can be considered as one of the most efficient solution for seismic performance upgrading of RC frame structures. This paper investigates the seismic behavior of RC buildings strengthened with different types of steel braces, X-braced, inverted V braced, ZX braced, and Zipper braced. Static non linear pushover analysis has been conducted to estimate the capacity of three story and six story buildings with different brace-frame systems and different cross sections for the braces. It is found that adding braces enhances the global capacity of the buildings in terms of strength, deformation and ductility compared to the case with no bracing, and the X and Zipper bracing systems performed better depending on the type and size of the cross section.