Acne or acne vulgaris is a skin disease that most often occurs in adolescents. One of the natural ingredients often used as a treatment is tea tree oil. However, there is a finding that tea tree oil is sensitive to pathogenic bacteria that make it resistant. Therefore, it is necessary to have an additional natural ingredient that can work synergistically with tea tree oil to increase the effectiveness of treatment against acne. One of the ingredients used is soursop leaf extract (Annona muricata). The emulsion was prepared by the spontaneous emulsification method and then incorporated into gel preparation. Three emulsion gel formulations were prepared with tea tree oil (5%) and different concentrations of soursop leaves extract (5%, 6%, and 7%). Afterward, physicochemical characteristics, antibacterial activity, antioxidant activity, and stability of the emulsion gel were investigated. The different concentrations of soursop leaves extract in combination with tea tree oil significantly affected the physicochemical characteristics, antibacterial activity, antioxidant activity, and stability of the emulsion gel. The best formula is formula 3 with 9,89±0,27mm of diameter inhibition zone and 66,75±0,005% of inhibition percentage. There is a synergistic relationship between tea tree oil and soursop leaf extract, as evidenced by an increase in the diameter of the inhibition zone, especially in the bacteria Propionibacterium acnes.