Objective: To investigate the contributions of components represented by characteristic peaks of fingerprints of total extract from Polygoni Cuspidati Rhizoma et Radix and its fractions of different polarity to antioxidant capacity in vitro. Method: The antioxidant capacity of total extract from Polygoni Cuspidati Rhizoma et Radix and its fractions of different polarity was evaluated using DPPH assay. HPLC method was introduced to determine fingerprints of the extracts. The correlation between fingerprint and antioxidant capacity was investigated by grey relational analysis. Result: The antioxidant capacity was resulted from the combined effect of multiple components. The order of contributions was(number of peaks) 8 >1>12(anthraglycoside B)>4(polydatin)>2>6 (resveratrol)>3>7>5>10>9>13>14(emodin)>11>15(physcion). Combined with the results in literature

peaks of No.11

14 and 15

the grey relational values of which were lower than 0.6

made no contribution under this experimental parameter condition. Conclusion: The spectrum-effect relationship of antioxidant capacity in vitro of Polygoni Cuspidati Rhizoma et Radix was investigated preliminarily

which would provide some reference for the study of pharmacodynamic material basis and spectrum-effect relationship of traditional Chinese medicine.