High performance liquid chromatography (HPLC) analysis showed that the content of chlorogenic acid in burdock standard water extract (BSWE) was about 1.22and#177;0.07 mg/g and no araciin and arctigenin was detected. The inulin was determined to be 174.33and#177;3.68 mg/g in BSWE by colorimetry method. The amino acids were analyzed by the amino acid analyzer and showed that asparagine and arginine are higher and determined to be 3021.00and#177;13.53mg/100g, 2042.33and#177;8.62mg/100g in BSWE, respectively. The results of aphrodisiac pharmacological experiments showed that the number of riding, insertions and the latency of rats in BSWE groups showed significant differences as compared with control, at the 7th day and 15th day after drug administration. Further study indicated that the aphrodisiac effect of BSWE is mostly associated with its regulation on NO, sialic acid and antioxidative ways and arginine should be one of the active components in BSWE.