Objective: To identify and assay of watersoluble dyestuff-lemon yellow and sunset yellow in Adulterated Rhizoma Belamcandae. Method: Use TLC for iddentification and HPLC-DAD for iddentification and assay lemon yellow and sunset yellow. Result: Both TLC and HPLC-DAD can identify lemon yellow and sunset yellow in Adulterated Rhizoma Belamcandae

and HPLC detection indicate the content of lemon yellow between 0.11-0.37 g·kg-1

and sunset yellow between 0.04-0.11 g·kg-1. Conclusion: Staining Iridis kectori khizoma or other adulterants with lemon yellow and sunset yellow as Rhizoma Belamcandae for sales is not only unnecessary

but also increase unsafe factors in clinic.It is necessary to pay attention to about this by relative medicine researcher and manufactory.