Objective To observe the effect of 15-KETE on voltage-gated K + (Kv) current in the intrapulmonary arterial smooth muscle cells ( PASMCs) of chronic hypoxic rats. Methods Twelve male SD rats matched with age and body weight were randomly divided into control and hypoxic groups. Single PASMCs were obtained with acute enzyme ( collagenⅠplus elastase) dispersing method. Using whole cell path-clamp technique in freshly isolated rat PASMCs from normoxic and hypoxic rats，the effect of 15-KETE on Kv current was recorded. Results ( 1 ) The resting membrane potential (Em) in PASMCs from chronic hypoxic rats was significantly depolarized to compared with that from normoxic control rats(P < 0. 05，n = 6) . The chronic hypoxia significantly inhibited the IKv of PASMCs from rats ( P < 0. 01，n =6) ，but did not alter the membrane capacitance (Cm) of PASMCs from rats. (2) The higher concentration of 15-KETE(1× 10 － 7 mol /L，1 × 10 － 6 mol /L) depolarized PASMCs from chronic hypoxic rats. (3) 15-KETE(1 × 10 － 8 mol /L ～ 1 ×10 － 6 mol /L) caused concentration-dependent inhibition of IKv in PASMCs from chronic hypoxic rats. ( 4 ) The percent inhibition that the higher concentration of 15-KETE(1 × 10 － 7 mol /L，1 × 10 － 6 mol /L) caused from chronic hypoxic rats was greater than that from normoxic control rats. Conclusions Hypoxia did not change the effect of 15 － KETE on the passive electrical properties of PASMCs. In both normoxic and hypoxic PASMCs，exogenous 15-KETE could cause concentration-dependent inhibition Kv current，and the inhibition of Kv current from hypoxic rats were greater than that from normoxic rats in higher concentration ( 1 × 10 － 7 mol /L ～ 1 × 10 － 6 mol /L) . Hypoxia might alter the sensitivity of PASMCs to 15-KETE.