Large energy consumption and increased environmental awareness in traditional method of asphalt production (Hot Mix Asphalt) have resulted in the innovation of a production technology named Warm Mix Asphalt (WMA). The logic of this technology is to reduce the viscosity of the bitumen and thus reduce mixing and compactio temperatures. The most two important results of temperature reduction are decreae of energy consumption and decreasing emissions of burning fuels, fumes and odors generated at the production plant and at the paving site. Besides these advantages, the produced WMA may have low moisture resistance because the aggregates do not loose their moisture completely. On the other hand Steel slags are the by-product of iron and steel factories that many researches have been done around the world to use this material in several fields. One of these fields is Asphalt Concrete (AC). Various studies show positive effects of the steel-slag on mechanical properties and improving moisture susceptibility of asphalt concrete. One of the properties of steel slags is high heat capacity in comparison to stone aggregate which leads to a higher energy consumption during the process of WMA production. The aim of this study is to use WMA technologies in steel slag hot mix asphalt in order to reduce the energy consumption leading to the production of steel slag warm mix asphalt (SSWMA). In order to produce steel slag warm mix asphalt, Sasobit which is an organic additive is used as an additive to decrease the viscosity of bitumen. This additive is used in the amount of 1.5% and 2.5% by weight of bitumen. The materials included binder (AC 60-70), Limestone and steel slag aggregates. To assess the performance of steel slag warm mix asphalt, several tests including Marshall tests, moisture susceptibility tests, indirect tensile strength, resilient modulus, rutting and dynamic creep test were applied. Also, Dynamic Shear Rheometer test was done in order to investigate sasobit effects on bitumen properties. Experimental results show that The addition of sasobit in mixture, results in 20°C reduction in mixing and compaction temperatures by decraese of bitumen viscosity. It is also concluded that the steel slag warm mix asphalt has a better performance than warm mix asphalt in the case of mechanical properties. Both slag warm mix and WMA had acceptable moisture resistance; but the moisture resistance of steel slag warm mix asphalt is much higher than that of warm mix asphalt. Keywords: Warm mix asphalt, Steel Slag, sasobit, Temperature reduction