Objective To study the effects of polysaccharides from Acer Saccharum on the growth of bacillus licheniformis and staphylococcus aureus in vitro.Methods Water was used to extract the polysaccharides,AB-8 resin was used to decolor and ion exchange resin was applied to deprotein.The refined polysaccharides of Acer Saccharum were obtained by the above method and preparated into polysaccharides solution of 50 mg/mL.The optical density of bacterial culture of four groups on 600 nm was measured every 12 hours with the method of UV spectrophotography.