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&NA; Allergic asthma is a chronic inflammatory disease of the airways. T lymphocytes play an important role in the pathogenesis of asthma. The voltage‐gated Kv1.3 potassium channel is a target for the preferential inhibition of TEM cells. In this study, we investigate the effects of PAP‐1, a selective inhibitor of Kv1.3 channel, on the treatment of the neutrophilic asthma model. PAP‐1 (40 mg/kg) was injected intraperitoneally into ovalbumin (OVA)‐lipopolysaccharide (LPS)‐challenged BALB/c mice. We found that the expression of the Kv1.3 channel in the lung tissues, and the intensity of the Kv current in the asthmatic mice increased clearly compared with those in normal control. PAP‐1 significantly reduced airway hyperresponsiveness (AHR), inflammatory cell count in the bronchoalveolar lavage fluids (BALF) and serum, and attenuated airway inflammation in a histological examination of the asthmatic mice. Moreover, PAP‐1 inhibited the OVA‐LPS‐induced imbalance of Th1/Th2, Treg/Th17 lymphocytes, and reduced levels of IL‐4 and IL‐17, inducing an increase in the production of IFN‐&ggr; and IL‐10. Furthermore, the activation of the extracellular signal‐regulated kinase (ERK)/nuclear factor‐&kgr;B (NF‐&kgr;B) pathway in the lungs of the asthmatic mice was suppressed by PAP‐1. We also found that PD‐98059, an inhibitor of ERK, had a similar effect with PAP‐1 in terms of regulating the imbalance of Th1/Th2, Treg/Th17 cytokines. However, PD‐98059 could not further influence cytokine changes when the cells were treated with PAP‐1. The results suggest that ERK acts as a downstream regulator of inhibitors of the Kv1.3 channel in neutrophilic asthma. In conclusion, the inhibitor of the Kv1.3 channel has therapeutic potential for treating asthma. HighlightsExpression and activities of Kv1.3 channel in lung tissue in asthmatic micePAP‐1 significantly reduced the airway hyperresponsiveness and airway, inflammation in asthmatic mice.PAP‐1 inhibited OVA‐LPS induced imbalance of Th1/Th2,Treg/Th17 lymphocytes.The mechanism may relate to the inhibiting the ERK‐NF‐&kgr;B signaling pathway