Ithas not found a complete system of theory on wetland science in the world. In this paper, wetland science was defined that: wetland science is a science to study formation and evolution law about wetland system. The main achivements of wetland research of China in the past 50 years were summarized: national marishs were indagated; lot of research results were made; some fields such as wetland system, wetland and global wetland classification et al, start to join in front of international research. Eight i...