Seroprevalence study was carried out on 423 donkeys and 48 horses of different ages and both sex for detection of the incidence of brucella. Seroreactive cases among donkeys at different locations in Assiut Governorate were 2.13%, 1.65% and 1.42% by using BAPAT, RBPT and TAT respectively, while by using Rivanol test (which detected the true positive only) it was 0.24%. Quantitatively, 6 serum samples were seroreactive using TAT; 5(1.18%) of them revealed titer 1/10 and last one (0.24%) had a titer 1/40 and also gave a titer 1/50 by using Rivanol test with a percent 0.24% (the only true positive case allover the study). Two cases only showed clinical sings with a titer1/10, the first had a history of abortion at the 7 month of pregnancy and the other had a sore back lesion. The incidence of infection among young donkeys (less than 5 years old) was less that of old ones (more than 5 years old) and in females it was higher than in males. There are no any seroreactive cases among the 48 examined horses using the above tests. It can be concluded that the disease was not widely prevalent among horses and donkeys reared in Assiut Governorate, however even this low percent among donkeys can threat human and others animals. BAPAT was the most sensitive tests for the serological detection of brucellosis among donkeys, and horses but TAT& Rivanol tests were the most accurate.