This chapter presents the comprehensive identification, quantification and discrimination in terms of distribution of phenolic compounds in different plants parts of the six Terminalia species, namely, T. arjuna, T. bellerica, T. bellirica, T. chebula, T. elliptica and T. paniculata using UPLC-QqQLIT-MS/MS. The UPLC-ESI–MS/MS data of the plant parts of Terminalia species were subjected to Principal component analysis to evaluate the variation among the six Terminalia species and simplify the data organization. It is an unsupervised clustering method without any information of the data set and retains maximum variance of multi-dimensional data while reducing its dimensionality. Significant differences were observed in the contents of the 37 phytoconstituents in the six species of Terminalia investigated. The contents varied in the plant parts leaf, stem, root, bark and fruit.