Beginning with research on socio-economic development of New York，this paper studies the intrinsic logics among socio-economic background，environmental quality and environmental protection measures of that city. In the past one century，the evolution history of New York’s environmental protection can be divided into four phases：respectively environmental protection capacity building phase，pollution-abatement-oriented phase，environmental-quality-oriented phase and residents-health-oriented phase，and this paper analyzes environmental policies and measures in different phases. Meantime，socio-economic development of New York City is closely linked with the neighboring areas of the metropolis；the city is the powerful engine of regional economic development and benefits from the inter-linked transportation system，talented labor force and mature infrastructure in the metropolis circle. In recent years，the tendency of closer socio-economic cooperation arises in New York Metropolis Circle，but segregation of administrative jurisdiction hinders implementation of regional planning and deeper cooperation in key fields such as transportation，energy，telecommunication and ecological protection. So，for many years，New York Metropolis Circle is exploring environmental cooperation scheme with New York City as the leader，the financial system as the bond and the special agency as the main executant.