This study was conducted on the impact  of  humic acid and  ascorbic acid supplementation on immunization against infectious bursal disease (IBD).Ninety  clinically healthy  avian  broiler chicks(one  day old )were  divided into three               equal    groups A,B and C.An attenuated live  IBDvirus(IBDV) vaccine was    administered at 14 day old in drinking water to all the experimental  chicks. Two        weeks post-vaccination, chicks of all groups were challenged with very virulent          IBDV   (field strain).Birds of group B were given humic acid (HA)and group C        ascorbic acid (AA)   from the   beginning till the end of the experiment as feed    supplement while group(A) kept  as control without any supplement .                                     Blood and serum   samples were collected during scarification on 39 and 49 day for hematological ,biochemical and immunological studies. Gross post-mortem finding; bursal indices ,average body weights and humeral ELISA antibody response to IBDVwere assessed Groups (B&C)showed Leukocytosis,elevated antibodies ,lymphocytic transformation index and   phagocytosis  percentage    beside elevated transaminasis .The  uric acid and creatinine   were significantly  elevated .The bursa  of  fabricius was slightly congested and swollen .The liver was  slightly  enlarged  and dark .