The formation of an amorphous layer is needed to prevent channeling effect of B in the subsequent implant and hence, shallower as-implanted and annealed profiles could be expected. B diffusion in the pre-amorphization (PAI) Si has been studied extensively by many research groups and the diffusion has been explained by the interaction of B and defects generated by the PAI and B implant processes. In our previous study, we found that B diffusion can also be affected by the immobile B clustering caused by the incorporated species and therefore, B diffusion in the PAI Si should be expected to be different with different PAI species due to their different effect on the B clustering. In this paper, we reported different B diffusion behavior in bulk Si with respective to different PAI species. The species include GeF2, Ge, F, BF2, and In and the immobile B clustering plays an important role in the B diffusion reduction.