As a result of the study, branched polysaccharides were isolated from the basidiomycete raw materials of Ganoderma lucidum. It has been established that the isolated fractions contain branched polysaccharides in the form of complexes with melanin. After purification of polysaccharides by ion-exchange chromatography, two fractions were obtained from basidial raw materials: neutral polysaccharides GW-1 with a yield of 25.71% and anionic polysaccharides GW-2, the yield of which was 5.26%, respectively. The physicochemical properties of the obtained samples were studied by IR and UV spectroscopy. The degree of purity of the obtained fractions of branched polysaccharides was established. Using gas chromatography, one-dimensional (13C NMR, 1H NMR) and two-dimensional (COSY, TOCSY, HSQC, HMBC, NOESY) NMR spectroscopy, the composition and molecular structure of the obtained polysaccharide samples were determined. The results showed that the isolated and purified polysaccharides are branched glucans with 1,4,6- and 1,3,6-bonds between glucopyranose units. Pharmacotoxicological studies were carried out on white outbred mice and it was found that the resulting polysaccharides belong to class V, practically non-toxic compounds (LD50 ≥ 2000 mg/kg). Isolated polysaccharides (GW) are promising biologically active components, on the basis of which it is possible to create drugs with hepatoprotective and antitumor activity.