Abstract:Microwave-assisted extraction was used to extract polygonatum polysaccharides and its antimicrobial activity was determinated. The results showed that material size， microwave power and microwave time appre－ ciable impact； the optimum conditions were： material size was 0.150 mm， the ratio of material to liquid was 1 ∶ 30 （g/mL）， microwave power was 350 W， microwave time was 2 min； under the optimized conditions， the ex－ traction rate of polygonatum polysaccharide could be up to 10.57 %. The experiment of antimicrobial activity showed that polygonatum polysaccharides had evident anti-microbial activities to Escherichia coli、Staphalococ－ cus aureus and Micrococcus luteus； the minimal inhibition concentration （MIC） was 2.00 % for Escherichia coli， was 1.00 % for Staphalococcus aureus and Micrococcus luteus.