The constituent elements of subrogation are as follows:
 1. The subrogated heir must die before the decedent.
 2. The subrogated heirs are only limited to the heirs of the deceased, and have not lost the right of inheritance.
 3. The successor in subrogation is the direct blood relatives of the successor in subrogation. The Civil Code includes the children of the brother and sister of the successor in subrogation into the scope of the successor in subrogation, expanding the scope of the successor in subrogation.
 The lineal relatives here include the imitated relatives by blood, such as the adopted children of the subrogated heirs and the stepchildren who have formed a dependency relationship. The grandson, grandchild, great grandchild and great grandchild of the decedent can inherit by subrogation, and the subrogation successor is not limited by the number of generations.
 4. Subrogation only occurs in statutory succession.
 [Legal Basis]
 Article 1128 of the Civil Code states that if a child of the decedent dies before the decedent, the direct younger blood relatives of the decedent's children shall inherit in subrogation.
 If the decedent's brother or sister dies before the decedent, the children of the decedent's brother or sister shall inherit in subrogation. The successor in subrogation can generally inherit only the share of the estate that the successor in subrogation is entitled to inherit.