[Objective] The situation of sustainable development of ecological-econorng-society system of urban agglomeration along Yangtze River delta were studied in order to support the sustainable development of the ecological economy of the urban agglomeration in this region.[Methods] Based on the emergy theory

the sustainable development of nature

economy and social system of urban agglomeration along the Yangtze River was studied. [Results] In 2017

29% of the ecological resources were over-exploited

with strong external dependencies

53% of cities had a low environmental load rate while 29.4% of cities had a high environmental load rate

11.7% of cities had low waste recycling capacity

47% of cities had low emergy exchange rates and strong economic competitiveness

35% of cities had high emergy currency rates

with low economic output efficiency

Shanghai and Suzhou cities had high emergy density per unit area

and 23.5% of cities had lower emergy density

29.4% of the cities had low per capita emergy welfare

17.6% of cities had a high population load rate

41.2% of the cities along the river were sustainable

and 58.8% of the cities were in over development situation.[Conclusion] In 2017

the urban agglomerations along the upper reaches of the Yangtze River were characterized by strong self-sufficiency

low environmental pressure

and excellent ecological quality. The urban agglomerations in the middle reaches coordinated with each other. The urban agglomerations in the lower reaches of the river were characterized by weak self-sufficiency

high environmental pressure

and poor ecological quality. Cities in Shanghai City and Southern Jiangsu Province had strong economic competitiveness

but their output efficiency was low. In Central Jiangsu Province and Central Anhui Province

except for provincial capitals

other cities had weak competitiveness. The economic development of cities in Southern Anhui Province laged behind and isolated along the river. The sustainable development of urban society in Shanghai City and Southern Jiangsu Province was excellent

forming a strong attraction to talents and resources

and they also had the problem of land shortage at the same time. The urban social

economic and ecological development of central Jiangsu Province were relatively balanced

but it had a weak attractiveness to surrounding cities. Except for Hefei City and Tongling City

the overall development of cities in central and Southern Anhui Province lags behind

and there was no effective attraction for surrounding cities. The overall sustainable development of the urban agglomerations along the river was still severe.