Objective:To investigate the effects of iptakalim (IPT),an adenosine triphosphate (ATP)-sensitive potassium channel opener,on the inflammation of hypoxic pulmonary artery hypertension(HPAH) in rats. Methods:A total of 96 SD rats were randomly divided into three groups (the control group,the hypoxia group and the hypoxia + IPT group,n=32 for each group). Hypoxia-treated and IPT-treated rats were placed into normobaric hypoxia chamber for 4 weeks (8 h/day,6 days/week). Eight rats of each group were killed at the end of each week. The right ventricle systolic pressure (RVSP) was measured and the small pulmonary arterial morphologic changes were detected by HE staining. Enzyme-linked immunosorbent assay (ELISA) was performed to analyze the content of interleukin-1β (IL-1β) and IL-10. Immunohistochemisty for ED1+ monocytes was performed to detect inflammatory cells around pulmonary arterioles. Results:IPT significantly inhibited RVSP increasing induced by hypoxia the remodeling of small pulmonary artery wall and the infiltrating of the arounding inflammatory cells. Moreover,IPT prevented IL-1β increasing and IL-10 decreasing induced by hypoxia in both peripheral blood and lung. Conclusion:IPT can alleviate inflammation in pulmonary vascular,lower the RVSP,antagonize the proliferation and remodeling of the small pulmonary artery. It is a promising candidate for the treatment of HPAH.