Abstract:Identification of green teas was made according to catechins and caffeine contents.Five varieties of green teas were tested in the experiment.First,the contents of catechins(epigallocatechin,epicatechincatechin,epigallocatechin gallate,epicatechin gallate) and caffeine were determined by HPLC.Then,Linear Discriminant Analysis(LDA),K-Nearest Neighbors(KNN),and Back-Propagation Artificial Neural Networks(BP-ANN) were applied comparatively to identify tea varieties as pattern recognition method.Experimental results showed that the best identification model was achieved by BP-ANN,and the identification rates for calibration set and prediction set samples were 98%and 92%,respectively.It is feasible to identify green tea varieties according to the analysis of catechins and caffeine contents by HPLC coupled with ANN pattern recognition.