Abstract: The present invention relates to a composition comprising an aqueous dispersion of particles (p) of mean hydrodynamic diameter between 50 and 5000 nm, the said particles containing in association: (A) polymers based on cyclodextrin units, comprising on average at least 4 cyclodextrin units within their structure; and (B) macromolecules of polysaccharides comprising groups G capable of forming inclusion complexes with the cyclodextrins present in the structure of the said polymers (A), with an average number of groups G per polysaccharide macromolecule at least equal to 3, the said compounds (A) and (B) being water-soluble in the isolated state. The invention also relates to the method of preparation of these compositions, as well as their use in order to achieve the encapsulation of compounds such as active substances.