It is described in the article the construction of the institution of affidamento fiduciario, as it is present in the statutory law of the Republic of San Marino. The institution is a surrogate device of the true English trust, but at the same time, it absolutely corresponds to the civilian categories. Despite it is the institution of the law of contracts, is has been created on the base of such institution of the law of succession as fideicommissum. The author pays attention to the fact that the main distinction between the affidamento fiduciario on the one hand, and the institution of entrusted administration (or fiduciary management) of the post-soviet legal orders on the other hand consists in that the contract of affidamento fiduciario establishes a kind of program in the interest of the beneficiaries which cannot be eliminated by termination of the contract. In case of breach of his duties by the fiduciary it is allowed only to replace him with another person. That is why the affidamento fiduciario is much more stable construction than the entrusted administration. Therefore it protects better the beneficiaries’ interest. Due to this the present writer as a drafter of the model law for the member-states of the Commonwealth of the Independent States “On entrusted administration and trust” borrowed the construction of the affidamento fiduciario as a model for the modification of the institution of the entrusted administration of property.