Background/Aims : Recently, an FDA-approved methacholine chloride ( Provocholine®) was introduced to Korea and widely used in the clinical practice. We aimed to evaluate the prevalence, risk factors and cutoff value of bronchial hyperresponsiveness (BHR) to Provocholine® in Korean 7-year-old general population. Methods : We recruited 2078 subjects in the initial cohort of the Panel Study on Korean Children. Among the subjects, 1577 mother-child dyads completed the 2015 annual follow-up, and 642 children visited the regional hospitals. We performed a standard spirometry, skin prick test and the bronchial provocation test via Provocholine® as well as a detailed history and physical examination in 16 regional hospitals. 559 children reliably completed bronchial provocation test. Results : Asthma was ever-diagnosed in around 7.7% of children, but the current asthma (wheezy episode in the last 12 months + diagnosed asthma by physicians) was found in 3.2%. Heightened BHR ( PC20 16 mg/mL) was observed in 25.8 % of children. The response dose ratio (RDR), a log-transformed continuous marker of airway responsiveness, was significantly elongated in current asthmatics than the others ( P=0.022). Moreover, there was a trend of increasing median RDR values across the groups of control, allergic rhinitis only, asthma only, and the combined allergic rhinitis and asthma ( P=0.001). Finally, the risk factors for current asthma were allergy rhinitis diagnosis ( P=0.018), history of bronchiolitis before the age of 3 ( P=0.004), recent use of analgesics/antipyretics ( P=0.027) and maternal history of asthma ( P=0.005). On the other hand, the risk factors for BHR were atopic dermatitis diagnosis and current dog ownership. The cutoff value of BHR to provocholine for the diagnosis of asthma in children was 5.8mg/mL (sensitivity : 47.1%, specificity : 87.4%). Conclusion : BHR assessed by Provocholine would give us useful clinical information. In the future, it is necessary to disclose the natural course of asthma and BHR through long-term follow up.