Based on the current importing and exporing regulations for disease control of embryo transfer, some important microorganisms and their control possibilities are reviewed. The results reviewed were sumrnarized as follows: 1. Regulations regarding to the import of embryos vary between importing and exporting countries, but exporting countries examine the donor and embryos for the heaith certification by the requirements of importing countries. 2. Organisms that infect the gametes are 5 kinds of viruses and the diseases caused by them could not be controlled or eradicated using embryo transfer. 3. Organisms that do not infect the gametes are 4 kinds of viruses and the causal organisms are potential candidates for control or eradication by embryo transfer. 4. Organisms that penetrate the zona pellucida and infect the embryo are 6 kinds of viruses including bovine viral diarrhea virus. 5. Organisms that cannot penetrate the zona pellucida or do not infect the embryo are 15 kinds of viruses and the removal from their contaminations are recommended by proper washing procedure and antisera treatment. Bovine and porcine parvovirus, porcine pseudorabies virus and vesicular stomatitis virus are included in these organisms. 6. Bovine embryos that artificially exposed to various pathogenic organisms such as bovine herpes virus, IBR virus, bluetongue virus, bovine viral diarrhea virus and Brucella abortus in vitro are discussed about their infection by several treatments.