Graft copolymers based on natural polysaccharides are promising materials for the development of biodegradable sorbents with a tunable set of properties. In this work, nine samples of a water-swellable graft copolymer of xanthan gum with acrylamide have been synthesized via radical microwave polymerization. The influence of the crosslinking agent introduction stage (initiation, propagation, or termination) and the mass ratio of the chemical reaction components, which determine the polymer network architecture, on the sorption characteristics of the obtained material have been investigated. It has been established that the sorption capacity of the graft copolymer in water (pH 7) and in a saline medium (20% NaCl, I = 3.4 M, pH 7) reaches 15.0 g/g, which exceeds the water absorption capacity of xanthan-containing sorbents described in the literature. The sorption capacity in 0.1 mM HCl (I = 0.1 mM, pH 4) and 0.1 mM NaOH (I = 0.1 mM, pH 10) decreases to 10.3 g/g but remains relatively high compared to similar sorbents. The degree of aqueous phase sorption correlates with the architecture of the spatial network: maximum water absorption is characteristic of samples with a high proportion of polyacrylamide, synthesized by introducing the crosslinking agent at the propagation or termination stages. The water absorption process in acidic and alkaline media is additionally infl uenced by conformational changes in the xanthan matrix, hydrolysis of polyacrylamide chains, as well as the location, number, and density of crosslinks of the macromolecular chain segments. The synthesized graft copolymer samples exhibit the ability to selectively extract the aqueous phase from a water-oil emulsion. The preservation of the material’s sorption properties under repeated swelling-drying cycles has been observed. In a model experiment using potting soil and test plants, the water-retention capacity of the studied samples has been revealed, as well as the absence of phytotoxicity. The combination of the obtained results allows the synthesized xanthan gum graft copolymers with acrylamide to be considered as promising environmentally friendly sorbent materials for the purifi cation of natural and industrial waters, the extraction of water from specifi c water-emulsion media, and as water-retention agents for agriculture and agribiotechnology.