One of the plants that had potential as a natural antioxidant was raja banana skin. The fraction of ethyl acetate of raja banana skin (Musa x paradisiaca L.) had antioxidant activity (IC50) with value 50.25 ppm. The fraction of ethyl acetate of raja banana skin will be formulated into serum gel. This study aims to determine the physical characteristics, physical stability and free radical scavenging of serum gel of ethyl acetate fraction of raja banana skin. Concentraions were used in formulation: 0.08 gram (F1); 0.16 gram (F2), 0.24 grams (F3). The raja banana skin was extracted using 96% ethanol by maceration method then be fractionated by using ethyl acetate. Serum gel was formulated by using carbopol as a gelling agent. It was tested for physical properties and physical stability for 28 days. Free radical scavenging activity was tested by DPPH method. Vitamin c as positive control. The results showed that the value of pH, viscosity, spreadability serum gel fraction raja banana skin fulfil requirements. Serum gel fraction of ethyl acetate was stable in 6 cycle because there is no significant change in serum gel, was seen by value of pH, viscosity, or spreadability. The IC50 value of serum gel fraction of ethyl acetate raja banana skin respectively: 87.947 µg/ml (F1); 84,297 µg/ml (F2); 71,257 µg/ml (F3). The IC50 value of positive control and negative control were 55,595 µg/ml; and 205,699 µg/ml. Statistical tests using one-way ANOVA showed that the activity of free radical catching activity of the three formulas was weaker than the positive control and fraction control used. F3 was best formulation with high antioxidant activity.