The objective of this study was to evaluate the anti-melanogenic effects of Hizikia fusiforme (HF) fractions in α-melanocyte stimulating hormone-induced B16F10 mouse melanoma cells. Ethanol extractions of Hizikia fusiforme (EEHF) were subjected to fraction by using dichloromethane (CFHF), ethyl acetate (EAFHF), butanol (BFHF), and water (WFHF). EEHF, CFHF, and EAFHF inhibited tyrosinase activity and melanin synthesis in B16F10 mouse melanoma cells in a dose-dependent manner. The melanin contents were inhibited by 40.5% and 33.2% in response to treatment with 50 μg/ml of EEHF and CFHF, respectively. In addition, tyrosinase activities showed a 53.3% and 54.1% reduction in treatment with 50 μg/ml of EEHF and CFHF. Western blotting analysis showed that EEHF, CFHF, and EAFHF inhibited tyrosinase, TRP-1, TRP-2, and MITF expression in a dose-dependent manner. In conclusion, these findings indicate that ethanol and dichloromethane fractions of Hizikia fusiforme, which inhibit melanin synthesis and tyrosinase activity, are effective skin-whitening agents.Key words : Hizikia fusiforme, melanogenesis, tyrosinase *Corresponding author *Tel : +82-51-890-1594, Fax : +82-51-890-2646 *E-mail : hhj2001@deu.ac.kr This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.