In this Paper an experimental investigation on the effect of Isfahan Ground Granulate Blast Furnace Slag (GGBS) on the compressive strength development of self-compacting concrete (SCC) and normal Concrete (NC) was performed. For this purpose, Portland cement type I was replaced with GGBS in various Portions. For NC and SCC Mixes 10*10*10 Cm Cubic specimens was tested in 7, 28 and 91 days. It must stated that in this research W/C=0.44, cement= 418 Kg/m³ and superplasticizer (SP) Type III used in SCC based on Polycarboxcylic acid. The results of experiments have shown that increasing GGBS Percentages in both types of concrete reduce Compressive strength in early ages.
