The idea of citizen science has a long history as old as Aristotle, and is broadly defined as public participation in real-world scientific investigation. People in Japan have traditionally engaged in citizen science activities and monitored changes in environment in their hometowns. Recently, many nationwide citizen science projects organized by governments, NGOs and museums were conducted and their contribution has been well recognized in the society. However, studies have found that citizen science in Japan is confronted with various challenges.

In the past decade, the amount of scientific data over large spatial and temporal scales obtained by citizens have been rapidly increased through the use of internet in the US and Europe. This new phase of citizen science just started in Japan. It promotes organized research in which public engage in the process of scientific investigations. Scientists and educators provide new ways to help answer scientific questions, achieve educational outcomes, and address issues of conservation. However, this growing citizen science faces several challenges such as 1) gaining acceptance as a real science, 2) linking science, education and conservation, 3) communicating across audiences and decision makers. By overcoming these challenges, citizen science can make significant contributions to conservation, management and policy.