High-quality development is the main focus of China's economic and social development in the 14th Five-year Plan (2021-2025) and even in a longer period. It is also the basic requirement to adapt to the changes of the main social contradictions and the key path to build a modern socialist country and the fundamental place to follow the law of economic practice. This paper constructs an evaluation index system of high-quality economic development from five dimensions of innovation, coordination, green, openness and sharing, and measures the high-quality economic development level of China's provincial-level regions from 2011 to 2018. On this basis, social network analysis (SNA) and quadratic assignment procedure (QAP) are used to analyze the structural characteristics of the associated network of high-quality economic development and the mechanism of the difference of high-quality economic development. The results show that: (1) The correlation degree of spatial correlation network has always been 1, and the network density is stable, between 0.2 and 0.26. The spatial correlation network with high-quality development of inter-provincial economy has strong accessibility, multi-overlap and certain hierarchy, but the correlation tightness needs to be improved, and the network indicators remain relatively stable. (2) The spatial association network of inter-provincial high-quality development can be divided into four sections, among which the "net spillover" section with western provinces as the main section benefits the least; The "agent" plate, which is dominated by the central provinces, plays the role of "intermediary" and "bridge"; The "bidirectional spillover" plate dominated by provinces in the Bohai Rim and the "net beneficial" plate dominated by provinces in the Yangtze River Delta and southeast coastal areas play a greater role in controlling and dominating the spatial association network, and exert a greater effect in polarization rather than trickle down in the process of high-quality development of national economy. (3) The regional differences of human capital, urbanization level, financial technology and environmental quality will directly lead to the differences of high-quality economic development level between regions, among which, the difference of human capital contributes more than 90%.

Keywords： high-quality economic development; spatial correlation network; social network analysis; quadratic assignment procedure; China