The invention relates to a cosmetic composition for skin whitening containing poria cocos wolf, ulmi cortex and licorice root mixture thereof. When the plant extract was used alone did not appear DPPH radical scavenging activity, reducing power and lipid peroxidation inhibition capacity prominently in the mix of these extracts showed significantly higher results in both the DPPH radical scavenging activity, reducing power and lipid peroxidation inhibition capacity, mixed that can be used in cosmetic products to show the effect whitening functional protein tyrosinase involved in melanin synthesis in the early stages to extract better than arbutin and inhibit the kinase activity of TRP-1 significantly reduces the effect known as the whitening functional ingredient