Constructing a green transportation system is necessity for the scientific and sustainable development of cities. The system's emergence and development are, reviewed here. It introduces the development patterns and experiences from London, Singapore and Hong Kong, as well as the the state and development planning of the domestic cities in different regions. Difficulties and problems existing in the development of the green urban transportation in our country are also summarized. Then, it proposes a strategic thinking, which is "constructing a comprehensive transportation system which highlights buses, slow-moving traffics and a proper number of environment-friendly cars as supplement". Finally, specific policy suggestions are given from different perspectives, such as idea, law and regulation, planning, installation, vehicle, management and supervision and so on. <<