Breast cancer has an incidence rate that always increases every year. One way to prevent cancer is the use of chemopreventive agents. Soursop Leaves (Annona muricata L.) and Tea Leaves (Camellia sinensis) are plants that contain flavonoids which are thought to act as antioxidants and can become chemopreventive agents. This study aims to determine the potential of Soursop Leaves and Tea Leaves as chemopreventive agents. The first stage of this research was to determine the presence of flavonoids in both of ethanol extract using TLC methode. Then to examine the antioxidant activity of the combination soursop leaf ethanolic extract and green tea leaves against free radical DPPH (1,1-diphenyl-2-pikrihidrazil). Docking molecular test of acetogenin and catechin compounds at HER2 and ER-α receptors which are biomarkers of breast cancer. Then optimization of effervescent granule formulation using wet granulation methode. The results showed that ethanol extract of soursop leaves and tea leaves containing flavonoid, shown with Rf value 0.66 and 0.68, and the rutin with Rf 0.66. The combination of both ethanolic extract has very strong antioxidant activity with IC50 value 26,90 μg/mL. The results using molecular docking of acetogenin and catechin compounds at HER2 receptors showed docking score of -6.3 kcal/mol and -6.7 kcal/mol and ER-α receptors showed a docking score of -6.5 kcal/mol and -7.6 kcal/mol. The most optimal effervescent granule preparation is formula number four with physical test results such as moisture content of 1.07% with a soluble time of 45.5 seconds and acidity of 6.18. The result show that Soursop Leaf ethanol extract (Annona muricata L.) and Tea Leaves (Camellia sinensis) have potential activity as chemopreventive agents and can be formulated into effervescent granule preparations.