In recent years, within the context of the growing trend of waste plant biomass reutilization, the potential of complex carbohydrates from secondary raw materials stands out, proposing the latter as novel ingredients, such as functional prebiotic oligosaccharides, for the functional food industry. Therefore, the aim of this study was to determine the composition of the carbohydrate fraction of the six secondary plant raw materials - sugar beet pulp, walnut shell, cocoa bean husk, onion peel, potato peel and pea pod. With the development of a reliable analytical methodology it was possible to determine content of carbohydrates in the dry matter of all samples and also content and composition of structural polysaccharides of all samples based on the characterization of the carbohydrate fraction. Analysis of macrocomponents reveiled dominant content of carbohydrates in the dry matter of all samples. Non-structural carbohydrates (glucose, fructose, sucrose) were determined in the range of 0.12% (cocoa husk) to 10.38% (pea pod). Structural carbohydrates, which were determined by means of soluble and insoluble dietary fiber content, accounted for most of the carbohydrate fraction. Correction of the latter for lignin content enabled determination of the content of structural polysaccharides, which ranged from 41,89 to 66,17% on dry matter basis, depending on the material. HPLC analysis of the hydrolysates of structural polysaccharides, with pre-column PMP derivatization, resulted in distinguishing monomeric profiles for each raw material. The proposed methodology as well as the results of this work will allow better planning of further activities aimed at recovery and reutilisation of carbohydrate fractions of different secondary plant raw materials.