Huh Jun(許浚, 1546-1615) accurately recorded distinctive symptoms of a disease: fever, headache, sore throat, dropsy, rash, and desquamation. These symptoms indicate that the disease is the same as those of scarlet fever described by contemporary medicine. If we compare Huh Jun's record with Daniel Sennert's, the first unequivocal record(1627) on the disease, Huh Jun also accurately recorded the sequence in which the rash appeared and then disappeared, being the first to note the "scaling" or "desquamation" which followed the rash. If so, Huh Jun's record on scarlet fever should be included in the early history of that disease. I do not think, however, that Huh Jun's investigation on scarlet fever has the historical value equal to that of Daniel Sennert. Unlike Sennert's, Huh Jun's investigation did not make a research tradition in the following ages: Huh Jun's report came to be neglected or forgotten in the history of Korean medicine. In Korean medical history, Huh Jun's investigation on scarlet fever has other two important features. First, he is the first Korean physician who made, independently from Chinese physician, an original exploration on a specific disease. At first we can easily find the reason in the fact that there were no medical books on scarlet fever in China at that time. In addition to that, we should remember Huh Jun had profound knowledge of medicine. As the author of Tongui-Pokam(「東醫寶鑑」)(1610) that synthesized East Asian medicine, Huh Jun dealt finely with the unknown disease. Second, denying supernatural etiology, Huh Jun explained the cause of the disease based on a naturalistic medical theory, Unkihak(運氣學).