Hypoxic pulmonary hypertension (HPH) is a common complication in patients with chronic obstructive pulmonary disease (COPD), sleep-disordered breathing, or dwellers in high altitude. The exact mechanisms underlying the development of HPH still remain unclear. Reactive oxygen species (ROS), hypoxia inducible factors (HIF), and potassium channels (K) are believed as the main factors during the development of HPH. We propose that the "ROS/Kv/HIF axis" may play an important initiating role in the development of HPH. Being formed under a hypoxic condition, ROS affects the expression and function of HIFs or K, and consequently triggers multiple downstream signaling pathways and genes expression that participate in promoting pulmonary vasoconstriction and arterial remodeling. Thus, further study determining the initiating role of "ROS/Kv/HIF axis" in the development of HPH could provide theoretic evidences to better understand the underlying mechanisms of HPH, and help identify new potential targets in the treatment of HPH.