Abstract: A total of 96 1day healthy AA broilers of commercial strain were chosen in this experiment, the birds were divided into 3 groups: control, test groupⅠand Ⅱ, four replicates of 8 birds were in a group. The total experimental time was 49 days. During 1～21 days, birds in test groupⅠand Ⅱ were fed basal diet supplemented with 0.1% alfalfa glycosides, respectively. During 22～35 days and the 36～49 days, birds in groupⅠwere fed basal diet supplemented with 0.1% alfalfa glycosides, and birds in groupⅡ were fed basal diet supplemented with 0.2 % alfalfa glycosides. The results showed that: ①Dietary supplementation of 0.1% alfalfa glycosides effects significantly the feed intake(FI) of the broilers in 22～35 days，but the performance difference of other groups and experimental times is not significant (P>0.05). ②Dietary supplementation of alfalfa glycosides to the different date age has the influence on serum and liver GSHPx, SOD and MDA level in different extend.

Key words: alfalfa glycosides; broilers; growth performance; anti-oxidation performance