The objective of this randomized, controlled study was to evaluate immunomodulating effects of Echinacea purpurea extracts (EP) and Astragalus extracts (AE) on infectious bursal disease (IBD) vaccination in broilers. Seven-day-old broilers (660 total) were randomly divided into 11 groups (A-K) of 60 chickens each. Each bird in Groups A, B and C received 2.5, 5.0 or 10.0 g/L EP drinking water respectively. Birds in groups D, E and F received AE at a dose of 30, 60 or 120 mg/L drinking water respectively and birds in Groups G, H and I received EP plus AE (2.5g+30mg, 5.0g+60mg, 10.0g+120mg respectively). Herbs were administered 7 consecutive days beginning Day 7 to Day 13. Group J (positive control) and Group K (negative control) received no herbs. Except for Group K, each bird in the other 10 groups was immunized with IBD vaccine on Day 13. The antibody titers to IBD vaccine, contents of IL-2, TNF-α, organ weight and body weight gain were obtained on days 14, 21, 28, 35 and 42 and analyzed by one way analysis of variance (ANOVA). Results demonstrated spleen and bursa index, body weight gain and antibody titers significantly increased after supplementation with EP and/or AE, especially in groups with EP 5.0 g/L, EP 10.0 g/L, AE 120 mg/L and all three groups with EP plus AE. The levels of IL-2 and TNF-α also significantly increased as antibody titer increased. Results indicated that EP and/or AP could be used as immune enhancement agents for IBD vaccine in chickens.