CMBD (a manually curated Cancer Metabolic Biomarker knowledge Database) is a resource integrating metabolic biomarkers scattered over literatures in PubMed. It contains 438 manually curated relationships between 282 biomarkers and 76 cancer subtypes among 18 sites reported in 248 literatures published before 31 December 2019 in English. Comprehensive information about cancers, biomarkers, reference, relationships, and samples is available. Users can click the link to access corresponding public resources for more credible detail information. Considering an interactive website, CMBD will be updated regularly according to user-submitted data and related literature published. It will help researchers and clinicians better understand the mechanism of cancers and develop new methods for cancer diagnosis, treatment, and prognosis.More figures about classification and statistics of biomarkers