The fungistatic effects of extract and crystal (A) of Berberis Koreans Palibin, a common shrub in Korea, were obeserved and compared with undecylenic acid and vegetable oil. In vitro studies, the spores of fungi were inoculated on Sabouraud s glucose agar media which contained compounds of various concentration, and the growth of the fungi was observed for 3 weeks. The species of the fungi used in these experiments were Epidermophyton floccosum, Microsporum gypseum, Microsporum audouini, Microsporum canis, Microsporum nanum, Microsporum cookei, Trichophyton rubrum, Trichophyton mentagrophytes, Trichophyton tonsurans and Trichophyton verrucosum. The results of the studies were as follows: 1. The growth of E. floccosum, M. audouni, M. canis, M. nanum, M. cookei, was inhibited in Sabouraud s glucose agar media containing extract and crystal (A) of Berberis Koreana Palibin 1 mg/ml.