In this article, we analyze the succession reserve, which is a legal limitation of the deceased's right to dispose of liberalities, whether it is liberalities mortis causa or donations. If there are reserved heirs and the deceased disposed of his property by donations or by will, the estate is divided into two: the estate reserve and the available quota. At the same time, the reserve is a part of the inheritance that is unavailable, under the law, to the deceased, it cannot dispose of it, in favor of other persons and to the detriment of the reservists. The reserve is calculated not on the inheritance that the deceased leaves but on the inheritance that he would have left, if he had not disposed through donations, and can be invoked only by the reserved heirs who have a useful (concrete) succession vocation, they did not give up in inheritance, they have succession capacity and are not unworthy. Reserved heirs cannot accept it before the succession is opened, nor can they give up the succession reserve.