Taiwan is located on the routes of migratory birds in east Asia area. There are thousands of migratory birds moving to Taiwan in winter. Many researches indicated many pathogens, including virus, bacteria and parasites are associated with the migration of birds. The purposes of the study are to understand the kinds of microorganisms that are carried by migratory birds and to evaluate the effect of these microorganisms to poultry industry and public health. The results of this study can be as references resources of disease surveillance, control and policy. It's also suggested that there might be immeasurable benefit effect to whole industry from this study.