The isoflavone as a derivatives of flavone is colorless crystalline compounds. It acts on synthesis of fibronectine, collagen III, collagen I in human normal fibroblast by same biological activity to animal hormone. In this study, we tried to search and demonstrate system content rate of dermal translocation system for cosmetics using microemulsion containing isoflavone. The results of microemulsion stability test by centrifugation, storage in incubator and circulation chamber showed that separation of phase did not appear after 30 days. By the skin flexibility test, it has confirmed efficiency and effect as cosmetics materials. As the result, the microemulsion showed that skin flexibility factor improved up to 7.6%. We could confirm that O/W type microemulsion was stable system.