Baikal Teal Anas formosa is a species of dabbling duck, distributed from far eastern Siberia to eastern Asia. It is a rare species, identified as a vulnerable by the IUCN. We examined the food preference of Baikal Teal by laboratory experiments. In the experimental cages, male and female Baikal Teal were kept separately and five types of grain (rice, soybean, wheat, millet and corn) were provided to them. The consumption rate was compared among foods. First, when the foods were given separately, wheat and millet were more frequently consumed. Secondly, when the five types of food were mixed and provided, millet was more frequently consumed. The results suggested that Baikal Teal preferred smaller sized grains than larger ones, such as soybean and corn