摘要:Geopolymer has been synthesized from fly ash to be applicated as water absorbent material. This research conducted to determine the ability of geopolymer to abrsop water by variation of solid – liquid ratio at optimum molarity of NaOH; 3 M. In this research, the synthesis of geopolymer was conducted at the variation of solid-liquid ratio; 60:40, 65:35, 70:30, and 75:25. Result of the treatment were characterized by XRD and SEM to compare the geopolymer structure. Water absorption capacity was measured by immersing the geopolymer specimens in water for 24 hours. Based on the result, solid – liquid ratio with maximum water absorbed was 70:30 with 13,04 wt%.