Bioactive substances, viscumneoside III (1) and homoflavoyadorinin B (2), were isolated from EtOAc fraction of korean mistletoe. The identity of the compounds was verified by spectroscopic means including 1H NMR and mass spectrometry. All spectral data are consistent with reported values in the literature. The isolated compounds were performed to identify the effect on tyrosinase inhibition activity compared to ascorbic acid as a control. All compounds showed the higher whitening activity than these of control. These results revealed that the whitening acivity of Korean mistletoe can be utilized for the skin cosmetics. This work was supported by Korea Institute of Planning and Evaluation for Technology in Food, Agriculture, Forestry and Fisheries(IPET) through Export Promotion Technology Development Program, funded by Ministry of Agriculture, Food and Rural Affairs(MAFRA)(313011-03).