To explore the immunological enhancing effect of traditional Chinese medicine compound extract made by ASTRAGALI RADIX, LIGUSTRI LUCIDI FRUCTUS, LYCII FRUCTUS AND CUSCUTAE SEMEN on immunosuppressed chicks. 180 SPF chicks of 3-day age were randomly divided into control group, model group, positive drug group, traditional Chinese medicine extract high, medium and low dose groups. The test groups’ chicks were established immunosuppressed chicks model by intramuscular injection with cyclophosphamide of 90 mg/kg for 3 consecutive days, and the control group was given equivalent physiological saline by the same way. Then, the traditional Chinese medicine extract high, medium and low dose groups were respectively added the medicine in drinking water of 10.0, 5.0, 2.5 g/L per day, and the positive drug group was added to astragalus polysaccharide powder of 200 mg/L per day for 7 consecutive days, the test period was 38 days. The results showed that the immunosuppressed chicks were added to the extract of 10.0 and 5.0 g/L could significant improve their final weight, daily gain and spleen index compared with model group(P<0.05). After 14 days of drug addition, serum IgM content began to be higher than that of the control group and maintained at a high level. After 21 days, the levels of serum IgA, IFN-γ and IgG of the medium dose group were significantly higher than the model group(P<0.05). Meanwhile, the antibody titer was increased after 7 days of inoculation of the infectious bursal disease(IBD) vaccine, and the high antibody titer level was maintained after 14 days of inoculation, which enhanced the immune effect of the IBD vaccine.These results indicated that the traditional Chinese medicine extract with the dose of 10.0 g/L and 5.0 g/L in drinking water could effectively enhance the growth performance of immunosuppressed chicks, their immune function, and the immune protection effect of IBD vaccine.