Abstract: The regression equation Y=0.949A+0.0002 and r=0.9992 of the relationship between concentration and absorbancewas established by determining the total content of flavones, in Qianshan semen cassias, assayed by the method of ethanolSoxhlet extraction and the method of spectrophotometers with the standard sample of rutin.

Key words: semen cassias, flavone Regression equation, the method of spectrophotometers