Abstract: The aim of this study was to investigate the effects of tea polyphenols（TP） on duodenal morphological development, antioxidant function and mRNA expression levels of intestinal tight junction protein genes in squabs to provide a theoretical basis for the rational application of TP as a functional feed additive in the production of pigeons. First, young pigeons（240 pairs, 1 day old,healthy, similar body weight） were randomly divided into four groups（control group fed on basal feed,100 mg · kg-1 TP treatment group, 200 mg · kg-1 TP treatment group, and 400 mg · kg-1 TP treatment group） with six replicates per group and ten pigeons per replicate（the content of TP≥ 98%）. After a 28 days feeding period, pigeon duodenum was collected for the detection of duodenum morphological development, antioxidant function and mRNA expression levels of intestinal tight junction protein genes. The results showed that when compared with squabs in the control group, feeds with TP could promote squabs’ duodenum development. Here, feeds with medium amount（200 mg · kg-1） of TP could increase duodenum intestinal villus height（VH）, crypt depth（CD）, velvet to hidden ratio（VH/CD）extremely significantly（P＜0.01） among squabs. Further, high amount of 400 mg · kg-1 TP could increase duodenum VH and VH/CD（P＜0.01） significantly among squabs. Besides, the results had shown that feeds added with TP could elevate intestinal antioxidant functions in TP-treatment groups compared with the control ones. Specifically, lower amount of TP（100 mg · kg-1） could decrease duodenum malondialdehyde（MDA） content extremely significantly（P＜0.01）, while medium amount of TP could reduce MDA content and lactic dehydrogenase（LDH） activities extremely significantly（P＜0.01）. Also,feeds with high amount of TP could lead to increasing in the total antioxidant capacity（T-AOC）,glutathione peroxidase（GSH-Px）, superoxide dimutase（SOD） activities and reduction in MDA contents and LDH activities extremely significantly（P＜0.01）. It displayed from the molecular levels that all the amount of TP could significantly increase the mRNA expression of SOD2 gene, and high amount of TP could also extremely significantly increase the expression of catalase（CAT） gene（P＜0.01）. For the effects of TP content on mRNA expression level of intestinal tight junction protein genes, it was found that feeds with a higher amount of TP might increase mRNA expression level of intestinal tight junction proteins in squabs. Here, feeds with low and medium amounts of TP could extremely significantly increase the expression levels of Occludin and reduce the Claudin-2 mRNA expression levels. Besides,feed added with a medium amount of TP could extremely significantly elevate the expression level of ZO-1 mRNA（P＜0.01）. Feeds added with high amount of TP could lead to extremely significantly increased mRNA expression levels of Occludin and ZO-1（P＜0.01）, significantly increased mRNA expression levels of Claudin-3（P＜0.05）, and extremelty decreased mRNA expression levels of Claudin-2（P＜0.01）. Overall, feeds added TP could improve morphological development, increase the intestinal antioxidant capacity and regulate the mRNA expression levels of intestinal tight junction protein genes in duodenum of squabs.