The Aim of this study is to investigate the effects of molarity of sodium hydroxide for alkaline solution on fly ash – GGBS based self-compacting geopolymer concrete using Foundry and. Self-compacting geopolymer concrete is improve the compaction without vibration and is made by fully eliminated of ordinary Portland cement content. The parameters studied were molarity of NaOH solution for alkaline solution and Partial replacement of foundry sand. The workability properties like, filling ability, passing ability and resistance to segregation were assessed by slump flow, V-funnel and L-Box test methods. It was found that the essential workability requirements for self-compacting geopolymer concrete according to IS 10262:2019 guidelines were satisfied. Results showed that the increase in strength and a decrease in workability of self-compacting geopolymer concrete samples were observed with the increase in molarity of NaOH solution from 8M to 12M and increase in foundry sand.