Macrofungi have long been used as a valuable food source and as traditional medicines around the world since ancient times especially in Japan and China. It was known that both fruiting body and the mycelium of mushrooms contain compounds with wide-ranging antimicrobial activity. In this study, hot water and cold-water extraction process were carried out to obtain polysaccharide from the fruiting bodies of Pleurotus eryngii mushroom. The crude polysaccharide extract obtained from the extraction was furthered evaluated for the antimicrobial activity. The antimicrobial activity was evaluated according to the disk diffusion method using Eschirichia coli (E.coli) bacteria. The hot water polysaccharide extracts were shown to inhibit the growth of E.coli bacteria and proved that it has an antimicrobial properties