To study the isolation,purification,structure properties and anti-inflammatory activities of polysaccharides from Sparassis subalpina.Response surface methodology was used to obtain the optimal processing conditions of total sugar from S. subalpina and the method of column chromatography was used for the purification of a S. subalpina polysaccharide (SSP).Using gas chromatography,NMR spectroscopy and electron microscopies,the structure was studied.Anti-inflammatory activity was determined using RT-qPCR,et al.The results showed that the experimental yield was (18.21 ± 0.68)% under the optimal processing conditions (liquid to solid ratio 80 mL/g,extraction time 60 min,extraction temperature 70 ℃).The average molecular weight of SSP was calculated to be 50 kDa and SSP consisted of glucose,mannose,galactose and arabinose with a molar ratio of 6.5∶1.3∶1∶1.The repeated unit in SSP was determined as →3)-α-D-Galp-(1→2)-β-D-Glup-(1→3)-β-L-Araf-(1→3)-α-D-Manp-(1→,and SSP showed a non-branched and netted state.SSP demonstrated significant inhibitory effects on the gene expressions of TNF-α,COX-2 and iNOS in LPS-stimulated RAW 264.7 cells (P<0.05).The results evidenced the potential effects of SSP with the non-branched and netted state on anti-inflammatory activities.