Complex vertebral malformation (CVM), a lethal autosomal recessive inherited defect in Holstein breed, was newly reported in Demark. If the proportion of CVM carriers in the nucleus breeding group of Holstein is high, great economic losses to dairy industry would be caused by the death of affected homozygous fetuses and the abortion of pregnant cows. The main symptoms and some important influences of CVM to dairy industry were reviewed, The process of researches on the CVM and the testing methods were explicated, and the status of potential CVM carriers in China was also discussed.