Abstract: Determination of soybean isoflavone content by three－wavelengths UV spectrophotometry was studied to eliminate the absorbance error of interfering components(such as oil).the problen of peak floating which varied changed with concentration change and the asymmetric absorption peak problems could be solved also.The method was more advantageous than traditional spectrophotometer method.The detection limit was 1μg/ml.The average recovery rate was 99.1％with RSD less than 3％.

Key words: Soybean isoflavones Determination.Three－wavelength UV spectrophotometry.