Face the serious resource and environmental constraint, the traditional development model of city is not sustainable any more. Green Economy that is a low carbon、resource efficient and socially inclusive economy. can solve the problems in city's sustainable development. UNEP releases the report "Towards a green economy" discusses that Green City is the direction of city's development. This Paper describes the green city on the aspect of connotation, evaluation criteria, development restrictions and policy recommendations, and last proposes the suggestions to the development of China's green city. <<