The prospect of identifying metallic impurities in p-type silicon has been studied by using the microwave photoconductive decay lifetime measurement method at various high injection levels. Samples intentionally doped with transition metals during crystal growth were prepared. It was found that point defects associated with Fe-B, Cr-B, and Ti, in decreasing order of effectiveness, degrade recombination lifetime in p-type Si.The effects of Fe-B pairs and Fe-B pair dissociation on recombination lifetime were also compared by various high injection levels.