Three novel polysaccharides (PCPW, PCPS1 and PCPS2) were isolated from Potentilla chinensis and subjected to structural analysis by using spectral and physicochemical methods. The molecular weights of PCPW, PCPS1 and PCPS2 were calculated to be 4.45 × 10³ Da, 1.18 × 10⁴ Da and 4.23 × 10⁴ Da, respectively. Analysis of monosaccharides composition confirmed that PCPW was composed of mannose, rhamnose, glucose, galactose and arabinose, while the two acidic polysaccharides PCPS1 and PCPS2 were consisted of six monosaccharides, including mannose, rhamnose, galacturonic acid, glucose, galactose and arabinose respectively. In addition, the main linkages of glycosidic bonds of PCPS2 were 1, 4-linked-rha, 1, 4-linked-man,1, 4-linked-galA and 1, 6-linked-man. Immunological tests indicated that both PCPW and PCPS2 could increase NO production of RAW264.7 cells, and promote splenocyte proliferation. All three polysaccharides proved to be activators of NF-κB. Overall, three polysaccharides showed a good immunological activity and pose great potential as a novel food or drug additive.