Corticotropin-releasing hormone (CRH) and its receptor (CRHR) play important roles in the hormonal response to stress by regulating the release of adrenocorticotropin (ACTH) from the hypothalamic-pituitary-in­terrenal axis and consequent secretion of glucocorticoids. In this report, CRHR1 cDNA was cloned by rapid amplification of cDNA ends-polymerase chain reaction (RACE-PCR) analysis and characterized by bioinformatics analysis. The expression profile of in different tissues was analyzed by quantitative real-time PCR and changes in expression with stress were detected following a cortisol injection. Serum glucose, cortisol, and ACTH levels were monitored after the injection. The full-length CRHR1 mRNA contained a 1290-bp open reading frame and encoded 429 amino acids. The amino acid sequence alignment showed that Carassius auratus CRHR1. The tissue expression analysis revealed that was expressed at high levels in the pituitary and hypothalamus, but lower levels were detected in liver, kidney, muscle, skin, and heart. Serum glucose plateaued at 2-24 h, serum cortisol peaked at 12 h, and serum ACTH and mRNA expression in different tissues did not change after the cortisol injection. A significant decrease in pituitary CRHR1 expression was detected immediately after the cortisol injection, whereas it increased significantly in the head kidney and heart. The change in hypothalamic CRHR1 followed a unimodal pattern of increasing slowly at the early stage and then decreasing slowly at the end. In conclusion, we cloned the full-length CRHR1 mRNA and detected changes in CRHR1 expression after a cortisol injection.