Abstract:Thin-layer chromatography and a dual wavelength TLC-scanner (Shimadzu CS-910)were used for the determination of hydroxygenkwanin and genkwanin in flos Genkwa before and after processing with vinegar. The result shows that the amounts of hydroxygenkwanin and genkwanin in processed products were increased. The amounts of the said two constituents were different in various products.