Objective: To analyze the suitable evaluation method of isoflavones in Semen Sojae Preparatum(SSP)

in order to analyze the scientificity of the method in Chinese Pharmacopoeia. Method:Based on the principle of fermentation

the differences of various analysis methods of isoflavone from SSP were analyzed; and HPLC method was used for the determination of daidzein

glycitein and genistein during the fermentation process of the pharmacopoeia group and the control group. Result:The linearity

precision

repeatability and stability of daidzein

glycitein and genistein were all good

with the average sample recoveries of 99.76%

99.96%

100.22%.Compared with the pre-fermented samples

the content of glycosides increased significantly in the post-fermented samples in the two groups. The total amount of isoflavone glycosides in the samples of the pharmacopoeia group was significantly better than that of the control group. With the 15-days post-fermentation as the end of fermentation

the content of isoflavone glycosides can reach about 1 212.23 μg·g-1. Conclusion: Since the previous dynasties

the production standard of SSP has been focused on full fermentation. According to the analysis of fermentation principle

the total molar mass of isoflavones in the fermentation process of SSP was unchanged or slightly decreased

and the content of isoflavone aglucones was significantly increased. The HPLC method was used to directly quantify the isoflavone compounds with a higher bioactivity

which was simple and highly sensitive and accurate. With the suitable standard established

it was effective to control the quality of SSP. SSP fermented by the pharmacopoeia method shows a better quality.