Abstract：Quantitative determination of thea saponin with purified saponin as standard by spectrophotometrywas studied. 8 0 o Vanilin-alcohol solution and 77 0 o sulfuric acid were used as colour reagents ,the wave-lengthmethodmethodis 452. Snm, the colour reacton temperature is 60'C and the reaction time is 15 minutes. Thisis easy to operate，less reagentwas suitable for the quantitativeconsumptiondeterminationand good repeatability. Results showed that theof thea saponin in industrial analysis.
