China is entering a new era with its economy turning to quality development from rapid growth. JJJ, as a new capital economic zone, plays a key role in demonstrating city cluster’s quality development. This paper, aiming at JJJ’s coalition in developing strategy for a quality city cluster’s quality development, this paper, based on JJJ"s 13 perfectures’ 2011 to 2020 data, uses the contents of quality development to establish a comprehensive evaluation index system for JJJ city cluster’s quality development, and employs entropy-TOPSIS model to estimate JJJ city cluster’s 2011 to 2020 quality developing index, and applies coupling coordination model & spatial autocorrelation model to study its coupling coordinating level, temporal-spatial evolutionary trend and spatial concentrating effect.The coupling coordination of JJJ city cluster’s quality development shows a weak-then-strong trend, with major cities in coordination in 2011 to 2015 changing to developing cities, at a decreasing coupling coordination, but rising after 2015. The coupling has been steadily rising, 84% of JJJ’s cities are rising in their coupling, most with strong correlation among economy, eco-environment, innovation, and civilian welfare. Temporal-spatial pattern of coordination has not changed, Cangzhou, Tianjin, Tangshan and Qinhuangdao have always been at the tier 2 except Beijing seats atop. Spatial evolutionary pattern of quality development suggests Beijing, Tianjin and Langfang are in the core area of city cluster’s quality development, radiating outward to southeast, falling toward northeast. Economy, eco-environment innovation and civilian welfare are the same. JJJ’s city cluster’s quality development has a positive overall auto-correlation, cities of high quality development are geographically closer, with outstanding spatial heterogeneity, their capitals are mainly located in the promoting area, Cangzhou, Hengshui and Qinhuangdao in the transition zone, and Langfang in the radiation zone, negatively correlated. A key mission for JJJ’s city cluster’s quality development is to make up the regional developing gap. This paper presents suggestions on accelerating industrial transformation to diminish regional gap, intensifying environmental cooperation to promote green development, activating regional resources to drive innovation, and jointly constructing public services to share the dividends.

To evaluate the key factors of Tianjin's oceanic resources environmental carrying capacity, this paper selects 27 indicators among oceanic resource system, oceanic environmental system and social economy system to establish an evaluation index system of oceanic resources environmental carrying capacity, with entropy-weighted TOPSIS model applied to evaluate Tianjin's oceanic resources environmental carrying capacity during 2007 to 2016 and its three sub-systems, key factors identified with gray correlation coefficient. In the period of 2007 to 2016, Tianjin's oceanic resources environmental carrying capacity amounts to 0.3412 to 0.5664, an intermediate level, showing a developing trend of descending-stabilizing-rising-stabiliing, descending during 2007 to 2010, stabilizing during 2010 to 2012, rising conspicuously during 2012 to 2014, and gradually stabilizing during 2014 to 2016. Tianjin's oceanic resources carrying capacity has a little change, its oceanic environmental carrying capacity shows a “V-shaped” trend and its social economic carrying capacity has a “W-shaped” trend. Gray correlation coefficient calculation indicates that key factors are annual sulfur dioxide and pollution control investment to GDP. This paper presents suggestions on rationally developing oceanic resources and developing coastal tourism aiming at improving Tianjin's oceanic resources environmental carrying capacity.