The main object of this study is to detect of brucella in cattle's milk collected from dairy farm by using different methods such as isolation, identification and typing of the isolates as well as comparative evaluation of the sensitivity, specificity between the different serological tests including ELISA test used for this purpose on milk and serum samples collected from cattle dairy farm in Sohag Governorates. A total of 110 cow's milk as well as 110 blood samples were collected and subjected to bacteriological and serological examination. Bacteriological examination of milk revealed that the Brucella organisms could be detected in 2.7% in cattle's milk. All isolates from milk typed as Br. melitensis biovar 3. The incidence of Brucella antibodies in milk samples were estimated by Milk Rosbingal Test (MRT) and by ELISA milk (mELISA) test. Out of 110 milk samples examined by MRT 19 (17.3 %) were positive and by ELISA milk test 13(11.8%) were positive of 110 milk samples. The MRT was taken as a reference standard for evaluating other tests. The sensitivity were ( 93.3%), ( 86.7%), ( 93.3%), (80%), (60%) and (53.3%) for each test, while the specificity were (92%), (96.6%),(92%), (96.6%), (100%) and ( 96.6%) for each and the agreement were (92.2%), (95%) , (92.2%),( 94.1%), (94.1%) and (90.2%) for BAPAT, wRBPT, wRiv.T, wTAT, wELISA and ELISA milk test respectively. In cow's milk samples, the sensitivity of MRT and ELISA milk tests were 100% and 43.8% while the specificity were 98.9% and 95% respectively. The sensitivity of blood serum tests including BAPAT, RBPT, Riv.T, TAT and ELISA tests in cow's serum samples the sensitivity were 100% , 66.7% , 100%, 100% and 66.7% respectively while the specificity were 100% for all. It can conclude that all isolates from milk typed as Br. Melitensis biovar 3. MRT is the most sensitive test in detection of Brucella antibodies in cattle's milk than other serological tests which help in early identification of infected herds.