According with the request of sustainable development for asset maintenance, in this paper the research state of China and other countries are indexed; then the contents of green maintenance were described and a system model of green maintenance was established. This paper discussed in brief the problems needing research, key techniques and adoptable methods of green maintenance. Based on the request of sustainable development for asset maintenance, in this paper the research state of China and other countries are indexed; then the contents of green maintenance were described and a system model of green maintenance was established. This paper discussed in brief the problems Need research, key techniques and adoptable methods of green maintenance.