Abstract: To study the changes of immunocompetence of polysaccharides from Codonopsis pilosula oral solution before and after autoclaving, the methods of alcohol precipitation and ultrafiltration membrane were used, the active polysaccharides of Codonopsis pilosula oral solution before and after autoclaving were obtained, and their immune activities were evaluated by measuring inflammatory responses in RAW264.7 macrophages of cell proliferation index, phagocytic index, NO release and secretion of cytokines (IL-6, IL-1β, TNF-α) .The results showed that the yields of polysaccharide fraction with molecular weight less than 30 k Da before autoclaving and autoclaving in Codonopsis pilosula oral solution (COP-2 and HCOP-2) were22.41% and 15.91%, the purity were 69.03% and 69.30%, respectively, and both of them could promote the proliferation of macrophages (proliferative index = 1.13~1.48) , which means they were the main active polysaccharidesin Codonopsis pilosula oral solution.Compared with COP-2, HCOP-2 decreased the phagocytic capacity, TNF-α and IL-1β production in the concentration range of 25~400 μg/m L (p < 0.05) , NO and IL-6 production were significantly decreased in the concentration range of 100~400 μg/m L (p < 0.05) , which indicated that autoclave resulted in decrease of immune activity of Codonopsis pilosula oral solution active polysaccharide.