Calculated coefficients of correlations between antioxidant activities (DPPH, RP and ORAC) and contents of active compounds (total phenolic and tannin) in blueberry leaf extracts were shown in Tables 3.Generally, the DPPH tests were highly positive with active compounds, while the results of RP and ORAC were found negatively correlated with active compounds. For scavenging effects on radicals, results indicated that in 50% ethanol and 70% acetone samples highest correlation was observed between TPC and DPPH (>97.8%),whereas in 50% and 95% ethanol extracts, good correlation was observed between Tannin and DPPH (86.2% and 97.7%). According to Table 3, a highly negative relationship existed between TPC and RP in methanol extracts (92.9%), and similar negative correlation was found in Tannin and RP in 70% acetone and methanol extracts with correlations being 96.7% and 93.1%, respectively. Moreover, TPC in 95% ethanol extracts (99.3%), and Tanninin 50% ethanol (98.1%) and methanol extracts (96.8%) were also well negative correlated with ORAC data.