This study was performed to confirm of biological function of black garlic, it heated for 11 days at $40{sim}90^{circ}C$ (first step: heate for 2 days at $90^{circ}C$, second step: heated for 4 days at $80^{circ}C$, third step: heated for 4 days at $60^{circ}C$ and fourth step: heated for 1 day at $40^{circ}C$). Samples were analyzed physico-chemical characteristics and antioxidant activity. Hunter L, a and b values were decreased during processing, and then inner part Hunter values were highly decreased at the second step. The moisture contents were decreased to 58.48${pm}$0.41 g/100 g at fourth step. pH was also acidified to pH 4.22${pm}$0.02, but O.D. value at 420 nm was increased during processing of black garlic. At fourth step, total phenolics and flavonoids contents were increased about 1.9 and 2.6 folds than first step sample. Also, total pyruvate and thiosulfinate contents were increased about 1.6 and 5.8 folds as change of total phenolic and flavonoid contents, respectively. Fructose contents were the highest level among free sugars and its contents increased to 2,454.45${pm}$4.20 mg/100 g. Contents of sucrose and maltose were decreased during processing of black garlic. The contents of total minerals were the highest at fourth step (1,009.20${pm}$6.91 mg/100 g) during its processing. Contents of glutamic acid, proline and aspartic acid were detected higher than other composition amino acids. Taurine and ethanolamine were not detected in the first step sample, but they were detected 0.88${pm}0.60{sim}1.06{pm}$0.04 and 0.28${pm}0.4{sim}0.5{pm}$0.09 mg/100 g in next processing step, respectively. DPPH radical scavenging ability of water and ethanol extracts from black garlic was increased during its processing. Abilities of DPPH radical scavenging were the highest in fourth step sample, its abilities were 67.40${pm}$0.21% in 1,000 ${mu}g/ml$ of water extracts. Reducing power was also significantly higher in water extract than ethanol extract on the whole.