Introduction:We have showed that frailty in COPD is associated with the hippocampal atrophy which is called ?brain frailty. However, non-invasive diagnositic tool for brain frailty in hippocamppus has not been developed. Aims and objectives:To explore diagnostic utiltiy of specifc frailty questionnaires, the Kihon Checklist (KCL) for hippocampal volume loss of COPD. Methods:40 patients with COPD and 21 healthy subjects participated in a cross-sectional study.We measured frailty score using KCL which consists of 1-25 questions and are categorized into 7 structual domains regarding instrumental and social activities of daily living, physical functions, nutritional status, oral function, cognitive function and depressive mood. Volumes of the hippocampal were obtained using anatomical MRI data).Results:Left hippocampal volumes were found to be significantly atrophic in the COPD than in the healthy (p?0.05). When adjusted by age and total brain volume, total KCL score (1-25) and left hippocampal volume showed significant negative partial correlations (?=-0.45, p<0.005).Moreover, the univariate correlation coefficient between the left hippocampal volume and KCL (1-5) which was domain regarding instrumental and social activities of daily living were largest (? = -0.51, p?0.001). Finally, we found that the KCL (1-5) score had a screening potential (80% sensitivity) for capturing bottom quartile of the left hippocampal volume at cut-off KCL (1-5) value of 2, namely if 2 of the 5 questions were applicable (AUC=0.78). Conclusion:The specific categorical frailty questionnaires regarding daily living inactivity are helpful to capture hippocampal frailty in COPD.