Objective: To determine whether histamine H3 receptor in the hypothalamic paraventricular nuclei (PVN) regulates the function of hypothalamic-pituitary-adrenal (HPA) axis in rats with asthma. Method: Rat model for asthma was established by Elwood’s methods. A stainless steel jacket was implanted into the PVN using a technique of central three-dimensional position, and R-(α)-methylhistamine [R-(α)-MeHA, a H3 receptor agonist] 2 μg or thioperamide (a H3 receptor antagonist) 5 μg was injected into the PVN. Levels of histamine in PVN were detected by high-performance liquid chromatography, and the concentrations of CRH in median eminence, ACTH and CORT in plasma were detected by the radioimmunoassay. Relative levels of IL-10 in both hypothalamus tissue and plasma were measured by double-ligand-linked immunosorbent assay. Result: Levels of histamine in PVN decreased significantly, whereas the concentrations of CRH in median eminence, ACTH and CORT in plasma and the levels of IL-10 in both hypothalamus tissue and plasma were all increased significantly in acute episode asthma rats with treatment of R-(α)-MeHA compared with control rats, and these responses were blocked by treatment of thioperamide, a H3 receptors specific antagonist. Conclusion: Specific activation histamine H3 receptors in PVN can improve the function of HPA in rats with asthma.