Public interest litigation is a litigation for protecting public interest.To some extent,the development of public interest litigation directly reflects a country's development of civilization.The researches on public interest litigation are so mature overseas that there has already been an integrated public interest protection system.In our country,with citizens’ increasing consciousness of law and right and with more and more infringement on social public interest,public interest litigation sprang up in judicatory practice,which makes public interest litigation become a focus both in theory circle and judicatory circle.