Abstract: To identify bovine freemartin syndrome, a disease caused by disorder of sexual organ development in co-twin heterosexual bovines, the peripheral bloods of seven Chinese Holstein freemartin cows were used to detect the existence of the XX/XY chimera by the way of droplet digital PCR（ddPCR）. The determination references was that the karyotypes of infertile twin calves and normal cows should be XX/XY chimera and XX, respectively. The results showed that all seven samples were suffering XX/XY chimera and were hetero-twin infertile, and the ddPCR could be an effective way of identifying the bovine freemartinism.