Abstract: In order to understand the infection status of bovine paratuberculosis in the scaled dairy farms in some provinces of China, a total of 16 172 bovine serum samples from dairy farms in Inner Mongolia Autonomous Region, Heilongjiang Province,Hubei Province, Sichuan Province, Anhui Province and Jiangsu Province were collected in 2015 and used to detect the antibody against Mycobacterium paratuberculosis. The total antibody positive rate of the samples for Mycobacterium paratuberculosis was2.59%, and the positive rate of Inner Mongolia Autonomous Region, Heilongjiang Province, Hubei Province, Sichuan Province,Anhui Province and Jiangsu Province were 2.09%, 3.90%, 2.05%, 5.23%, 8.00% and 1.22%. The antibody positive rate of the dairy farms with different scales was as following： the large scale dairy farms was 2.42%, the moderate scale dairy farms was2.01%, and the small scale dairy farms was 4.32%. The antibody positive rate of the small scale dairy farms was extremely significantly higher than that of the moderate scale dairy farms（P0.01）, and was significantly higher than that of the large scale dairy farms（P 0.05）. It was indicated that the infection rate of Mycobacterium paratuberculosis in the scaled dairy farms in Anhui Province, Sichuan Province and Heilongjiang Province was higher, and the antibody positive rate of the large scale dairy farms was lower than that of the moderate and small scale dairy farms. The results of epidemiological investigation of bovine paratuberculosis obtained in this study offered reference for the control of this disease in China.