OBJECTIVE：To screen the components with better anti-inflammatory effect from Codonopsis Radix polysaccharide and explore the anti-inflammatory mechanism. METHODS ：Using Codonopsis Radix as sample ，the crude polysaccharide （CP） was obtained by water extraction and alcohol precipitation. After CP was separated and purified by Fast Flow DEAE Sepharose ， SephadexG-150 gel column and so on ，the components CP 1-2-1 and CP 3-1-1 were obtained and then characterized. The survival rate of RAW 264.7 cell was determined by MTT method after cultured with CP ，CP1-2-1 and CP 3-1-1（0.01，0.1，1，10，100 μg/mL）for 24 and 48 h respectively. The cells were divided into blank group （blank culture medium ），model group （1 μg/mL LPS）and low-，medium- and high-concentration groups of 3 kinds of Codonopsis Radix polysaccharide （1 μg/mL LPS+25，50， 100 μg/mL CP，CP1-2-1，CP3-1-1 solution）. After cultured for 24 h，NO content in cell culture solution ，mRNA expressions of TLR4，IL-6，NF-κB and TNF-α in cells were determined. RESULTS：The sugar content of CP reached （92.20±0.73）％. CP 1-2-1 was a single neutral polysaccharide composed of fructose with a relative molecular weight of 25.8 kDa. CP 3-1-1 was an acidic heteropolysaccharide composed of arabinose ，rhamnose，galactose and galacturonic acid and so on ，with a relative molecular weight of 49.5 kDa. Cell survival rates were higher than 99％，after cultured with 3 kinds of polysaccharide for 24 and 48 h. Compared with blank group ，NO content in cell culture solution and mRNA expressions of TLR 4，IL-6，NF-κB and TNF-α in cells were increased significantly in model group （P＜0.05 or P＜ . Compared with model group ， NO content in cell 2016CFB412） culture solution of each administration group was significantly reduced，mRNA expressions of TLR 4，NF-κB，TNF-α，IL-6 in cells in 50，100 μg/mL CP group were significantly decreased ong1991@163.com （P＜0.05 or P＜0.01）；mRNA expressi ons of TLR 4，NF-κB in cells in 25 µg/mL CP 1-2-1 group and mRNA expressions of TLR 4，NF-κB，TNF-α，IL-6 in cells in 50，100 µg/mL CP 1-2-1 group were significantly decreased （P＜0.05 or P＜0.01）；mRNA expressionsof IL- 6 in cells in 25 µg/mL CP 3-1-1 group，mRNA expressions of NF-κB，TNF-α，IL-6 in cells in 50 µg/mL CP 3-1-1 group and mRNA expressions of TLR 4，NF-κB，TNF-α，IL-6 in cells in 100 µg/mL CP 3-1-1 group were significantly decreased （P＜0.05 or P＜0.01）. CONCLUSIONS ：CP，CP 1-2-1 and CP 3-1-1 all have certain anti-inflammatory activities. The mechanism may be related to inhibiting the generation and releasing of inflammatory cytokines such as TNF-α，IL-6 by inhibiting the activation of TLR 4/NF-κB pathway.