The basidiomycetes Ganoderma lucidum, Hericium erinaceus, Lentinus edodes and Trametes versicolor were used for preparation of aqueous extracts. A polysaccharide preparation (VPG) was isolated from the G. lucidum aqueous extracts. The mycelium was grown under submerged conditions according to an original procedure. Preliminary exposure of mice with tumors to cyclosphosphamide in a low dose for prolonged elimination of T-suppressors and rapid recovery of T-killers induced an increase in the efficacy of the H. erinaceus and L. edodes extracts. Investigation of the aqueous extracts and VPG on different tumor strain lines for the potential Modifiers of Biological Response (Ca755, s/c P388, s-180) demonstrated antitumor activity and satisfactory tolerabily after oral administration. Inhibition of the tumor growth by the H. erinaceus and T. versicolor extracts and VPG amounted to 88-99% and that of s-180 treated with the L. edodes aqueous extract amounted to 66-75%. Compositions 1, 2, 4 amd 5 were significantly more active by the duration and value of the effect on the animal tumor nodes as compared to the aqueous extracts and VPG included to the compositions and composition 4. Composition 5 (T. versicolor + H. erinaceus + G. Lucidum) proved to be the most efficient by all the criteria. The results of the design of the technologies for cultivation of the mycelum of the medicinal basidiomycetes, investigation of the antumor properties of the extracts and polysaccharide fraction of the mycelium and development of efficient compositions on their basis are summarized. Composition 5 proved to be the most promising for the clinical trials.