In order to study the effect of coptidis antidotal powder (CPD) and flavomycin (FLA) on the structure of intestinal microflora in the ileum of broilers,one hundred and eighty one-day-old AA broilers were randomly divided into three groups:basal diet (CK),basal diet with 5 mg/kg FLA (FLA group),basal diet with 1.25 g/kg CPD (CPD group).The results showed that the diversity of ileal microflora decreased with the increase of age, and the abundance of operational taxonomic unit (OTU) in FLA and CPD groups at 35 days of age was significantly lower than that at 15 and 25 days of age (P<0.05).Compared with the control group,dietary FLA significantly decreased the relative content of 10 genera in ileal flora of 35-day-old broilers,such as Flavobacterium,Streptococcus and Amycolatopsis (P<0.05),and CPD significantly decreased the relative content of 6 genera in ileal flora of 35-day-old broilers,such as Klebsiella,Flavobacterium and Amycolatopsis (P<0.05).There were also significant differences in the metabolic pathway and protein function of ileum microbial community among different treatment groups.At 35 days of age,compared with FLA group,the signalling molecules and interaction function of ileal flora in CPD group increased significantly (P<0.05),while transcription and cytoskeleton decreased significantly(P<0.05).It could be seen that CPD supplement in broiler diet could regulate the structure of ileum microbiota, similar to FLA.The metabolic pathways of the functional genes in different microbial communities were found to vary with diet.