Saniculiphyllum guangxiense as a highly distinctive species within Saxifragaceae is fallen to the critically endangered category, whose chemical and taxonomic information is still little-known. The first time LC-DAD/MSn investigation on S. guangxiense led to the detection and characterization of 50 compounds, involving cyanogenic glycosides, phenolic sulfates, triterpenoids, amino acids, phenyl-propanoids, aromatic derivatives, lignans, flavonoids, nucleosides, fatty acids and carbohydrate, based on their fragmentation characteristics, UV spectra or comparison with the reference compounds. The collision induced dissociation (CID) fragmentation patterns for several types of compounds were also concluded. The main constituents of S. guangxiense were revealed as cyanogenic glycosides, triterpenoids, phenolic sulfates and organic acids, which were very different from other Saxifragaceae plants. This paper will provide valuable information for understanding its chemical profiles and taxonomic position in Saxifragaceae from a chemotaxonomic point of view. (C) 2014 Elsevier B.V. All rights reserved.