Objective: To establish UPLC chromatograms of different botanical origins of Sinapis Semen and Raphani Semen before and after being processed

and to study on the change law of chemical composition in three kinds of Chinese herbal pieces before and after being processed. Method: UPLC was used with ZORBAX Eclipse XDB-C18 column

acetonitrile-0.1% formic acid solution containing 0.08 mol · L-1 ammonium formate was employed as a mobile phase in gradient elution

detection wavelength was 254 nm and flow rate was 0.3 mL · min-1. Result: Seven common peaks were observed in the raw and stir-fired decoction pieces of Sinapis alba

the area of main peaks of S. alba was significantly changed after being fried

and a new peak a was generated

but the original peak 8-10 disappeared.There were ten common peaks in Brassica juncea and its stir-fried product

and the area of some peaks of B. juncea was significantly reduced after being processed

and the peak 11 almost disappeared.There are six common peaks in the raw and stir-fired decoction pieces of Raphani Semen

and the area of main peaks of Raphani Semen was significant changed after being processed

and the peak a disappeared

and 2 new peaks were formed.By analyzing UPLC chromatograms of Sinapis Semen and Raphani Semen

all these three Chinese medicine decoction pieces belonged to sinapine thiocyanate

but there were significant differences in area and number of main peaks. Conclusion: UPLC chromatograms of Sinapis Semen and Raphani Semen can comprehensively reflect the material basis of decoction pieces

as well as their change law before and after processing

it provides experimental basis to reveal processing principle of the three Chinese medicine decoction pieces

and to further interpret the scientific connotation of processing generic principles of Chinese medicine decoction pieces containing glucosinolates.