A preliminary investigation was made on variabilities of five species of Korean Entomobryidae, four Homidia and one Entomebrya, using scanning electron microscope and isozyme analysis by electrophoresis. from Homidia species no distinctive interspecific features were observed in integumental configurations, dental spine structures and ocelli shapes.“Dental spinet”and annotations of fourth antennal segments of Homidia, however, may not be considered definite characters distinctive enough to differentiate this genus from Entomebrya as formerly conceived, because of their much vague developments in some species. Zymograms of esterase, catalase, leucine aminopeptidase and general protein revealed prominent polymorphism in general. In Homidia koreana the population from Mt. Jiri-san, of somewhat distinctive color pattern from those of Mt. Yongmum-san and Jeonju area, revealed also some difference in zymograms although all of them can be regarded as the same species for their Identical chaetotaxy. Consequently, the chaetotaxy, in Homidia at least, may be considered questionable as a character sensitive enough to reflect any genetic differentiation and concomitant speciation attained by the groups concerned.