Background: The growth of cells is closely related to components in a culture medium. There are many reports about cellular characteristics of melanocytes grown in a PMA-contained medium. However, only a few reports have been studied by using a physiologic mitogens-contained medium. To understand melanocyte in vivo, it is necessary to know the cellular biology of melanocytes grown in a physiologic mitogens-contained medium. Objective: To investigate any differences between melanocytes grown in phorbol 12-myristate 13-acetate(PMA)-contained medium and in physiologic mitogens-contained medium. Method: We examined morphology, number and melanin contents of cultured human melanocytes grown in a PMA-contained medium and physiologic mitogens-, such as bFGF, ET-1 and a a-MSH contained medium. Result: The results are summarized (continue...) (Korean J Dermatol 1999;37(2): 168-176)