Thirty nine kinds of Korean herb drugs have screened for antimicrobial activity of some pathogenic microorganisms. It was revealed that some of hot water extracts from herb drugs showed antimicrobial activity in one or more strain of pathogenic microorganisms. Phellodendron amurense and Coptis chinensis inhibited growth of Staphylococcus aureus. Rubus coreanus showed antibacterial activity in Staphylococcus aureus and Pseudomonas aeruginosa. Citrus unshill inhibited growth of Escherichia coli and Cornus officinalis showed antibacterial activity in E. coli and Pseudomonas aeruginosa. Dioscorea battltas and Cinnamomum cassia showed antibacterial activity in Pseodomonas aeruginosa. And also, ScutelJa baicaJerrsis inhibited growth of Candida albicanus. Achyranthes japonica and Glycyrrhiza uralensis showed antifungal activity in Aspergillus niger. It was noteworthy that Glycrrhiza uranensis inhibited growth of Staphylococcus aureus, E. coli, Pseudomonas aeruginosa and Aspergillus niger.