Striving to develop an ecological civilization is a grand strategy of the Communist Party of China to achieve harmonious development of the social economy and of resources and the environment. The strategy is an aggressive response to the grim reality that the social economy is being developed at the cost of resources and the environment. As a focal center of society, the economy, culture, and population, the megacity in China is a place where the issue of resources and environments is foregrounded. Therefore, the construction of an ecological civilization in a megacity has a particularly important role to play in the overall strategy of developing China's ecological civilization. Though issues relating to resources and environments are different in megacities compared with mid-sized and small cities, within the different megacities there are commonalities in terms of the ecological environment and the current status of ecological civilization construction. There is, therefore, an urgent need to develop an evaluation index system for ecological civilization construction that reflects the particular features of issues pertaining to resources and environments in megacities. This would enable the construction of an ecological civilization at this mega scale in alignment with the evaluation results. Our paper focuses on ecological civilization construction in megacities. Based on our analysis of the current status of megacities and the prominent contradictions that exist between issues relating to resources and environments and socioeconomic development, we established an index system for evaluating ecological civilization in megacities. This system includes 20 indicators, covering the following four aspects: the degree of ecological and environmental health, consumption intensity of resources and environments, efficiency of non-point pollution governance, and residential livability. Considering national standards, policy and planning requirements for each indicator, and the development goal of each indicator established through correlational research, we evaluated the performance of ecological civilization construction efforts during the period from 2006 to 2011 in Wuhan. Our evaluation results show that Wuhan should take pertinent countermeasures regarding ecological protection, conservation of resources and energy, non-point pollution regulation, and livable city construction to push forward its efforts to construct an ecological civilization. These countermeasures include the following: (1) Wuhan should further control levels of inhalable particles, reduce the sulfide level in the atmosphere, recycle waste water resources, control the scale of sewage discharge, and control noise pollution in urban areas. (2) The city should markedly reduce energy consumption, exhaust emissions, and industrial solid waste emissions per unit of GDP, and should pay more attention to controlling their total amounts and intensity. (3) Abilities to regulate and comprehensively utilize the city's domestic sewage and household garbage should be improved, and renewable "mineral products" arising from urban living should be recycled. (4) Special efforts should be made to improve the percentage of forest coverage and the urban greening rate, to reduce population density, and to resolve issues of housing and traffic congestion.