Diffractive Production of $b bar b$ in Proton - Antiproton Collision at the Tevatron

We show that the cross section of the diffractive production of $b bar b$ can be described as the sum of two contributions: the first is proportional to the probability of finding a small size $b bar b$ color dipole in the fast hadron wave function before the interaction with a target, while the second is the $b bar b$-production after or during the interaction with the target. The formulae are presented as well as the discussion of the interralation between these two contributions and the Ingelman- Schlein and coherent diffraction mechanisms. The main precdition is that the coherent diffraction mechanism dominates at least at the Tevatron Energies, giving the unique possibility to study it experimentally.