This study determines the effect of the initial pressure on the propagation of a Chapman-Jouguet detonation wave from a stoichiometric C 3 H 8 /O 2 mixture (donor) to a stoichiometric C 3 H 8 /air mixture (acceptor). Depending on the initial pressure ratio in the donor and the acceptor, the result can be a smooth transmission, a re-initiated detonation wave, or a transmitted shock wave. When the donor is divided into a driver donor and a driven donor, the degree of overdrive in a driven donor varies with the donor pressure ratio. There must be a greater degree of overdrive in the driven donor for re-initiation of a detonation wave in the acceptor, particularly if the initial pressure in the driven donor is lower than the Chapman-Jouguet pressure in the acceptor. The bi-dimensional effect is also another major factor.