The expression of Bax,TGF-β₂,TGF-β₃ and Ghrelin in the stomach and small intestine of Asio otus after starvation was investigated by immunohistochemical staining,and their expression intensity was analyzed semiquantitatively by a stereological method. The stomach and small intestine showed immunoreactivity of Bax, TGF-β₂ ,TGF-β₃ and Ghrelin. Bax immunopositive cells were mainly distributed in the single-layered columnar epithelial cells of stomach mucosa,intestinal mucosa,intestinal glands and the single-layered cuboidal epithelial cells in deep glands of the glandular stomach. TGF-β₂ and TGF-β₃ immunopositive cells were mainly localized in the single-layered columnar epithelial cells of the mucosa of the glandular stomach,simple tubular glands of muscular stomach,intestinal mucosa,intestinal glands as well as the single-layered cuboidal epithelial cells in deep glands of the glandular stomach and lamina propria in small intestine. Ghrelin immunopositive cells weremainly distributed in the single-layered columnar epithelial cells of the intestinal mucosa,intestinal glands as well as the single-layered cuboidal epithelial cells in deep glands of the glandular stomach and lamina propia of small intestine mucosa. The expression of Bax showed the maximum in the glandular stomach,decreased progressively from glandular stomach to duodenum,and then increased from duodenum to ileum. The expression of TGF-β₂ and TGF-β₃ showed the maximum in the duodenum. The expression of TGF-β₂ decreased progressively from duodenum to ileum,while the expression of TGF-β₃ increased from glandular stomach to duodenum,decreased progressively after duodenum,and then increased in ileum. Ghrelin immunopositive cell density gradually decreased from the glandular stomach to the ileum. Bax,TGF-β₂ ,TGF-β₃ and Ghrelin may participate functional regulation of stomach and small intestine.