Background: The rind of red watermelon (Citrullus vulgaris subrum) contains a terpenoid compound is lycopene which has an antibacterial activity for acne. Nanoemulsion are known to increase the penetration of substances on the skin because they are influenced by the addition of surfactants and cosurfactants. So it is necessary to make nanoemulsion by combining Tween 80 and PEG 400. This study aims to determine the effect of the combination of Tween 80 and PEG 400 on the percent transmittance, viscosity, pH, and determine the good stability of the optimum formula. Methods: Watermelon rind was extracted by the maceration method using 96% ethanol as solvent. The manufacture of nanoemulsion using the spontaneous emulsification method and designed in the Design Expert 13.0.0 program using the Simplex Lattice Design (SLD) method. Results: Based on the results of the study showed that the composition of Tween 80 of 47,726% and PEG 400 of 17,277% resulted in the optimum formula with a predicted value of %Transmittance 98,737%, viscosity 930,160 cps, pH 5,65, desirability value 0,874 and particle size 17,1-18,6 nm. Conclusion: The preparation of red watermelon rind extract nanoemulsion with a combination of Tween 80 and PEG 400 give a significant effect on % transmittance and viscosity and stability did not give significant changes in centrifugation, organoleptic, viscosity, pH, and nanoemulsion type tests.