Soibirhym(Portulace oleracea) was extracted by methanol and its antimicrobial activities against food spoilage or foodborne disease microorganisms were investigated by the paper disc method. The microorganisms used in this experiment included 5 species of bacteria(Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Klebsiella Pneumoniae, Staphylococcus aureus) and 3 species of fungi(Fusarium solani, Aspergillus flavius, Penicillium citreonigrum). Soibirhym showed high antimicrobial activites against P. citreonigrum, P. aeruginosa and K. pneumoniae. Minimum inhibitory concentrations(MICs) on S. aureus, P. citreonigrum and K. pneumoniae were 200, 200 and 250 mg/㎖, respectively. In the methanol extracts from Soibirhym, 147 kinds of compound were separated by GC/MS. The extraction yields of phenolics, furans, alcohols, acids and esters, ketones, aldehydes, and miscellaneous compounds were 7.43%, 6.13%, 2.20%, 41.06%, 9.21%, 0.15% and 1.08%, respectively. Some antimicrobial compounds such as 2,3-dihydro-benzofuran, 4-hydroxy-3-methoxy-benzoic acid, 4-hydroxy benzeneethanol were detected in the methanol extract.