To establish an objective quantitative discrimination method for rapid differentiation of raw Semen Coicis,bran-fried Semen Coicis and Semen Coicis Preparatum,to provide scientific basis for process standardization and quality standard of different Semen Coicis decoction pieces,and to provide reference for the differentiation of other traditional Chinese medicine processed products.Methods:L*,a* and b* of raw Semen Coicis,bran-fried Semen Coicis and Semen Coicis Preparatum powder were determined by the spectrophotometer,and E*ab was calculated.The correlation between different Semen Coicis decoction pieces and their L*,a* and b* was statistically analyzed.The discriminant mathematical model and 95% confidence intervals of different Semen Coicis decoction pieces were established.Results:The rank sum test and Spearman's rank correlation showed that L*,a* and E*ab were highly correlated with the samples(P<0.05,|r|>0.8),and could be used as a criterion for determining the relationship between different Semen Coicis processed products and the three important parameters.By Wilks' Lambda and Fisher discriminant analysis,standardized discrimination of different Semen Coicis decoction pieces was realized,and specific linear discriminant functions were established:raw Semen Coicis=447.378L*+393.192a*-289.087E*ab-6 664.567; Semen Coicis Preparatum=268.996L*+321.422a*-116.086E*ab-6 352.510; bran-fried Semen Coicis=538.049L*+470.526a*-384.469E*ab-6 330.551,which were verified by cross discrimination and 3D scatter plot of L*,a* and E*ab.Conclusion:It was feasible to digitize the appearance and color of different Semen Coicis decoction pieces by spectrophotometer and carry out discriminant analysis on them in combination with statistics.The established discriminant model could provide reference for identifying traditional Chinese medicine.