Abstract: Macrophages play an important role in host defense in phagocytosis, cytotoxicity, antipresenting, cytokines secretion, regulating internal environment and antitumor effects. Previous studies showed that polysaccharides had the effects in antitumor and modulating macrophage activities. More and more polysaccharides were developed for its immune modulating activities in macrophage and the recent researches mainly focused on investigating the receptors and signal transduction mechanism responsible for the immune modulation by polysaccharides. 

Key words: polysaccharides; macrophage; receptor; mechanism