The author explores the problem of Tiberius’ place in Augustus’ plans at the beginning of the 20-ies B.C. This period is usually ignored both in the biographies of Tiberius and in special research dealing with the dynastic policy of Augustus. The article also analyzes the position of Tiberius in comparison with that of his coeval Marcellus and of his brother Drusus at the same age, the betrothal of Tiberius with one-year-old Vipsania and the actual position of Agrippa between 26 and 24 B.C., when the general had no formal powers. The author concludes that during the 20s BC Augustus was planning that in the future his elder stepson would take the place near Marcellus similar to that of Marcus Agrippa near Augustus, the place of the second most powerful man in the state, the closest acolyte of the ruling princeps. Apparantly, according to Augustus’ project, the pair Marcellus – Tiberius was eventually to replace his union with Agrippa in the state.