This investigation is performed on 100 buffaloes native Breed in Kaliobia governorate Egypt aged from 1-3years, these animals suffered from fever (41℃) enlargement lymph node, inappetence, pale mucous membrane, increase lacrimation, emaciation and corneal opacity in progressive stages when these animals were subjected to microscopic examination the degree of parasitaema was recorded as the percentage of infected red blood cells in 1000red blood cell counted .We report the detection of Theileria annulata by PCR in blood samples obtained from buffaloes supposed to be infected. The assay employs primers specific for the gene encoding Theileria annulata 185RNA biochemical changes associated with Theileria annulata in these buffaloes particular emphasis to the oxidative stress the reduce TAC level may reflect adecrease in antioxidant capacity . Blood collected from all animals on EDTA to microscopic examination and PCR to determine type of Theileria.