Based on the basic judgment of identification standards and spatial structure of urban agglomerations in China, this paper considered that "15+8" spatial structure system comprised of 15 compliance and 8 non-compliance of urban agglomerations was the present structure of formation and development of urban agglomerations in China. The main conclusions were as follows. Firstly, analyzing the "three high" characteristic comprised of high-density cluster, high-speed growth, high-intensity operation of urban agglomerations in China, this paper put forward: 1) "Four Low" problems containing low development degree, low input-output efficiency, low compact degree, low resources and environmental protection degree, 2) "Four Competition" problems comprised of blindly competing for national strategies regardless of own condition to strive for national pilot area, expanding their power regardless of the red line to trigger a large-scale land to construct cities, leading to the so-called high degree of integration with competing for construction repeatedly regardless of cooperation, breeding area deprivation with drawing up high goals careless for the resources and environmental capacity; 3) "Four-off" problems containing excessive intervention of government and administration, high estimated of the development prospects, dense negative effect of the clustering size, large development gap and 4) "Five Missing" problems comprised of lack of unified identification standard of urban agglomerations, lack of standardized statistical data, lack of centralized management with specific authorities, lack of accepted planning approach and implementation institution, lack of planning legal status of urban agglomerations. Secondly, this paper brought forward the overall development strategy and construction goals of urban agglomerations in China and thought that it would form national urban agglomerations spatial structure system comprised of 23 urban agglomerations, 6 urban agglomerations gathering area and "π" shaped urban agglomerations continuous band. Finally, some policy support mechanism and countermeasures suggestions for the construction of urban agglomerations in China were put forward: 1) to formate a national-level and local-level coordinated development management committee of urban agglomerations, public finance mechanisms and public financial reserve system for urban agglomerations, 2) to revise Town and Country Planning Act or to introduce Regional Planning Act which will add the content of urban agglomerations planning and draft treaty for cooperation of urban agglomerations, 3) to introduce Urban Agglomerations Planning Approval Approach and Urban Agglomerations Planning Implementation Management Ordinance and to build urban agglomerations planning implementation institution, 4) to introduce technical guide to guide scientific planning for urban agglomerations and to strengthen resources and environmental protection capacity and sustainable development capacity of urban agglomerations, 5) relying on the rapid land-axis and speeding up to construct the 7 918 national highway network and "four vertical and four horizontal" high-speed railway network for improving rapid transit system of urban agglomerations, and 6) to specify standards of statistical data and compile and publish Statistical Yearbook of Urban Agglomerations in China.