Two PCR primer sets and two oligonucleotide probes verified from the sequence of transcription units of DNA ( ribosomal DNA, rDNA) encoding the small Subunit ribosomal RNA (SSr-RNA)genes of B. bovis and B.bigemina, Mexico strain ( one set /each ) were used to amplify a portion of these genes from both species in Egyptian cattle. The expected fragments by Polymerase Chain Reaction (PCR) were visualized and measured as 275 base pair (bp) and 175 (bP) corresponding to B. bovis and B. bigemina respectively. The amplified products were confirmed by Southern blot hybridization with nonradioactive (NR) species specific oligonucleotide probe. The sensitivities of these methods were 200 parasite /ml blood in B.hovis and 15 parasites/ml. of blood in B bigemina. By the PCR method 30% of carrier cattle were infected with B. bovis and 40.9 % with B.bigemina as well as 4.5% showed mixed infection, while with microscopical examination of Giemsa stained blood smears only 1.8% were detected. Cattle which were positive microscopically revealed the fragment of B. bigemina by PCR. This method provides a useful diagnostic tool for rapid detecting and testing the efficacies of drugs and vaccination used.