For quality control of buckwheat, fingerprint-efficacy study of buckwheat was carried out in this work. 2,2´-Bipyridyl,2,2- diphenyl-1-picrylhydrazyl radical (DPPH) scavenging activity of the buckwheat was measured using UV spectrometer. Chemical fingerprints of tartary buckwheat from 29 different sources were determined by HPLC-UV and investigated by similarity analysis and hierarchical clustering analysis. The fingerprint-efficacy relationship between chemical fingerprint and DPPH radical scavenging activity of tartary buckwheat were established by multi-linear regression analysis. The results showed that the sources of buckwheat had some important influence on the chemical fingerprints and DPPH radical scavenging activity. DPPH radical scavenging activity of tartary buckwheat was stronger than that of common buckwheat, rutin, and kaempferol and some unknown compound might be the major effective components for quality control of tartary buckwheat for its antioxidant activity.