Soybeans (Glycine max (L.) Merr) was known to contain flavonoids that have antioxidant activity which can inhibit the formation of free radicals (Reactive Oxygen Species) causes’ premature aging. This study was aimed to determine the effect of fermented soybeans antioxidant activity and determine physically stable gel formulation. The fermentation process used Lactobacillus plantarum. Determination of antioxidant activity was measured by DPPH method. The results showed fermented soybeans has higher antioxidant activity of IC50 value 87.17 mg/mL compared to unfermented soybeans with IC50 value 59.26 pg/mL (P<0.05). The fermented soybeans were incorporated to the gel formulation with HPMC concentration variations. Based on the evaluation for 28 days is known that gel preparation is physically stable, homogeneity result showed the similarities of color, spreadability test result over a range of 6 cm - 4.1 cm, the measurement of pH value of P<0.05 and viscosity measurements P<0.05.