Six purple-black barberry accessions (Berberis vulgaris L.) were obtained from various sites in Sivas province of Turkey. Fruits were analyzed for their total phenolic (TP), total monomeric anthocyanin (TMA) contents and for their antioxidant capacity by the ferric reducing antioxidant power (FRAP) and TEAC assays. Sugar and organic acid composition were also determined by HPLC. TP and TMA contents were measured using the Folin-Ciocalteu reagent and pH differential methods, respectively. Variability between the accessions was not high. Variability among accessions was greatest for FRAP content (C.V. 17.9%); individuals ranged from 41.0 to 65.6 ${mu}mol;TE{cdot}g^{-1}$ on a fresh weight basis. Variation among the accessions was also evident for TP, TMA, and TEAC values (C.V. 16.21%, 14.85%, and 7.13%, respectively). The major sugars of barberry fruits were glucose ($8.84g{cdot}100mL^{-1}$) and fructose ($6.12g{cdot}100mL^{-1}$) and dominant organic acids were malic ($7.59g{cdot}100mL^{-1}$) and citric ($1.34g{cdot}100mL^{-1}$). Within this limited study of six different accessions, chemical profile and antioxidant capacity of barberry fruits have rich source of natural antioxidant substances.