NOVELTY - Nanostructural biocide composition (C1) comprises nanoparticles of bentonite powders intercalated by zinc ions and by at least one ion selected from silver and copper.    USE - As a nanostructural biocide composition, with fungicidal and bactericidal activity (claimed), which is used in construction, medicine and other various areas of techniques in compounds for preventive prolonged antiseptic treatment of premises with long stay of humans, for treatment of surfaces of constructional units including medical purposes and for synthesis of compounds which are biocompatible with tissue of an alive organism and preferably intended for external use for treatment of skin diseases, trophic ulcers, burns, inflammatory infiltrates.    ADVANTAGE - The composition is in liquid form, which is safe ecologically and toxicologically. The presence of the liquid environment in a composition of biocide improves the process of its distribution on the treated surfaces, and provides the maximal microbiological efficiency that is desirable at industrial application. The compositions are not toxic, do not cause an allergy, have no contra-indications and possess high antiedematous, sorption, ion-exchanging and antiinflammatory properties.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the nanostructural biocide composition (C1) involving: a) enrichment of a bentonite in sodium (Na)-form with Na+ ions, by treatment with a 3-10% water solution of sodium chloride, subsequent washing up to removal of acid anions and drying; b) treatment of the product obtained in stage (a) with a 10-20% water solution of an silver (Ag) salt, preferably silver nitrate, at a temperature corresponding to its solubility in water, followed by washing until removal of sodium salts and by filtering and drying; c) treatment of the product obtained in stage (a) with a 10-20% water solution of a zinc (Zn) salt, preferably zinc chloride, at a temperature corresponding to the water solubility of the salt, followed by washing until removal of sodium salts and by filtering and drying; d) treatment of the product obtained in stage (a) with a 10-20% water solution of a copper salt, preferably copper sulfate, at a temperature corresponding to water solubility of the salt, followed by washing until removal of sodium salts and by filtering and drying.