In this study, essential oils were extracted from the leaf of Chamaecyparis obtusa (CLEO), indigenous to Korea, CLEO constituents were analysed, and the effects of CLEO on airway hyperresponsiveness (AHR) and airway inflammation (AI) were investigated in Ovalbumin (OVA)-induced asthma mouse model. Terpenoid components among identified CLEO constituents made up more than 80%. The CLEO-treated group in comparison to the control group showed reduced AHR, the decrease of eosinophil number in the bronchoalveolar lavage fluid (BALF), reduced specific anti- OVA IgE level in the serum, and a significant reduction in Th2 cytokines levels in the BALF with concentration. We concluded that CLEO have an alleviating effect on asthma-like symptoms such as AHR and AI. Further studies about antiasthmatic effect are necessary on the focus of single component of CLEO.