Ornithology has been stocked huge amount of knowledge during its long history in science, and that can be a big advantage to use birds as model systems for ecology, conservations and many other fields. Birds are often in important position as keystone and/or umbrella species in food web in various ecosystems. Therefore, the predator-prey interactions between birds and their prey have been attracted attention not only in basic ecology also applied fields like as agriculture and conservation. However, the interactions between birds and molluscs are much less surveyed than between birds and insects, despite many species of birds depend on molluscs as their food resource. Avian food resources are also well researched in Japan, however there is no reviewed database that mentioned about the exact species of molluscs as the food habit of birds. It is important to figure out the exact interaction between predator and prey in species level in terms of basic ecology and conservations for both predator and prey species. In this study, we classified the main diet of all Japanese bird species, listed out the detail information of molluscs in avian diets, and evaluated the molluscs as the food habits of birds according to the information available in the literatures.