OBJECTIVE： To optimize the extraction technology of polysaccharides from antlion and explore its effect on immune functions of mice. METHODS： Using content of polysaccharides as investigation index， the effects of extracting polysaccharides from antlion by water extraction method protease hydrolysis extraction （optimized by orthogonal test using extraction temperature， enzyme dosage， extraction time as indexes）， and diluted alkali extraction （optimized by orthogonal test using alkali concentration， extraction temperature， extraction time as indexes） were compared. 128 KM mice were randomly divided into 4 groups， then randomly divided into control group （normal saline）， polysaccharides low-dose， medium-dose， high-dose groups （20， 40， 80 mg/kg）， 8 in each group， iv in tail vein， 0.2 mL/10 g， once a day， for 1 week， which were respectively used to determine the phagocytosis percentage and phagocytic index of peritoneal macrophages， spleen and thymus index， lymphocyte transformation rate and serum hemolysin levels. RESULTS： The contents of polysaccharides by 3 methods were 14.48％， 38.66％， 30.62％， respectively. The content of polysaccharides by protease hydrolysis extraction was the highest， the optimal extraction technology were as follows as using 100 μg/g papain extracting 3 h under 40 ℃. Compared with control group， phagocytosis percentage， phagocytic index， spleen index in polysaccharides low-dose， medium-dose， high-dose groups were significantly increased （P＜0.05）， thymus index was significantly decreased （P＜0.05）， while lymphocyte transformation rate had no significant changes （P＞0.05）； serum hemolysin in polysaccharides medium-dose group was significantly increased （P＜0.05）. CONCLUSIONS： Protease hydrolysis extraction is suitable for the extraction of polysaccharides from antlion， the optimal technology is reliable. Polysaccharides from antlion show activity in enhancing mice non-specific immunity and humoral immunity.