A wavelength conversion method was established to determine chlorogenic acid, luteolin and luteoloside in Lonicera japonica leaves. The content of chlorogenic acid in aqueous phase was 2.05%, while the content of luteolin and luteoloside in EA phase were 1.12% and 0.57%, respectively. The antioxidative activity of effective components in Lonicera japonica leaves was evaluated by DPPH?, FRAP and ORAC with Vc as reference substance. The results showed that crude extraction, crude fraction, chlorogenic acid, luteolin and luteoloside in Lonicera japonica leaves all had great antioxidative activity. The strongest antioxidant capacity substance was luteolin, its IC50 value, reducing capacity and ORAC value were 0.01764 mg/mL, 1751.8±13.9 mmol/L and 23817.44 μmol Trolox/g, respectively. The crude fraction eluted by 30% ethanol also showed high antioxidative acitivity, its IC50 value, reduction capability and ORAC value were 0.02548 mg/mL, 933.8±11.6 mmol/L, and 10557.97 μmol Trolox/g, respectively. The antioxidative activity of each constituent increased with the increase of concentration and purity of the antioxidant. Therefore, there is broad development and utilization prospect of the antioxidant activity constituents of Lonicera Japonica leaves as a new type efficient non-toxic antioxidant.