Connexion 43 (Cx43), a gap junction protein, is expressed abundantly in the airway and has been implicated in the pathogenesis of asthma. However, the effects of blocking Cx43 in asthma remain unclear. We investigated the therapeutic effects of two specific Cx43 inhibitors (Gap26 and Gap27) on the development of allergic airway disease in mice. Allergic asthma was induced in BALB/c mice by sensitization and challenge with ovalbumin (OVA). Different doses of Cx43 inhibitors were administered by aerosol inhalation 1 h after OVA challenge on days 21 and 23. Airway hyperresponsiveness (AHR), lung pathology, mucus production, and inflammatory cells and cytokines in bronchoalveolar lavage fluid (BALF) were examined. We found that Gap26 significantly inhibited OVA-induced AHR, inflammatory cell infiltration surrounding the bronchia, mucus production, inflammatory cells and cytokines in BALF, and OVA-specific IgE in the serum in a dose-dependent manner. Gap27 showed effects similar to those of Gap26 in inhibiting inflammatory cytokine production in BALF. We conclude Cx43 inhibitor inhalation alleviates asthma featuresin mice and may be a promising therapy for clinical asthma.