Abstract: To investigate the effect of rating polysaccharides by alcohol in astragalus polysaccharides on the serum interleukin-2 contents in chickens. By using three different concentration levels of alcohol to get rating polysaccharides in APS: A1, A2, A3; 320 one-day-old chickens were randomly divided into eight groups, experimental groups and control group were hypodermic injected A1, A2, A3, A1+A2, A1+A3, A2+A3, A1+A2+A3 and distilled water separately for seven consecutive days, and then draw blood on the 22nd, 29th, 36th, 43rd, 50th, 57thday to detect serum interleukin-2 contents, and evaluate the immune adjuvant effect of rating polysaccharides. A2, A3, A2+A3, A1+A2+A3 can increase serum interleukin-2 contents. The valid targets of APS are A2, A3.

Key words: astragalus polysaccharides (APS); rating polysaccharide; interleukin-2