ABSTRACT Concrete is the most popular material used in the construction works in which cement is the main composite. The manufacturing of cement involves the emission of greenhouse gases into the atmosphere which are responsible for global warming. Hence the researches are currently focused on various materials to replace and reducing the cement utilization. Moreover, in this contribution the concrete Geo-polymer has been made with GGBS (granulated ground blast furnace) along with steel fibers mixing. GGBS is the by-product produced from steel industry. Steel fibers are added to increase the tensile strength of concrete. In this experimental investigation geo-polymer concrete containing GGBS and steel fiber (0.5%) with 8 Molar and 10 Molar alkaline activators are used. The ratio of these alkali activators is 1:2.5. The results showed that fiber can significantly enhance the Mechanical properties. The enhancement also increases with the increasing fiber volume fraction.