Since the reform and opening up, China's rapid urbanization has boosted the development of economy and society, but it is also confronted with tremendous challenges. The multidisciplinary research has promoted the issue of National New-type Urbanization Planning, which indicates the transformation of China's urbanization strategy. Further research, however, is needed to explore the theoretical construction of China's new-type urbanization. The paper summarizes the development process of China's urbanization and points out its characteristics, which includes peri-urbanization, special national conditions, complicated factors and governance system. China's urbanization makes a great contribution to the world. Moreover, the literature demonstrates the significance of urbanization to the discipline of human and economic geography and the scientific connotations of new-type urbanization, which refers to peiple-oriented, harmonious, inclusive and sustainable. Under the background of the humanism transformation, new-type urbanization should transform from population urbanization to people-oriented urbanization. There are six crucial scientific issues: people-oriented urbanization and equalization of basic public services, urbanization with integrated and coordinated development of urban and rural, urbanization in the context of resources and environment carrying capability and climate change, diverse regional modes, spatial effect and mechanism, as well as big data and innovation of technical methods. The paper makes efforts to illustrate a framework of China's new-type urbanization connotation, which provides references for theoretical research and policy formulation.

Spatial correlation is the link of regional interaction and influence; the urbanization spatial correlation is spatial relationship of urbanization based on population flow, which influences and continuously adjusts the regional economic and social development pattern in China. By analyzing the change of the spatial correlation intensity and the spatial correlation network of provincial urbanization in China during 1990-2015, this paper reveals the spatial correlation characteristics, formation process and influencing factors of China's provincial urbanization since China's reform and opening up. The results show that: (1) 7 types of spatial correlation intensity are identified in the evolution of provincial urbanization of China, among which the dominant type has the highest degree of coincidence with the whole country, and determines the evolution process of the spatial correlation intensity of urbanization in China. The non-dominant types of urbanization spatial correlation intensity evolution feature 2005 as the critical year, and their growth was slow or even negative before the year; then together with the dominant type, they have promoted a continuous increase in the urbanization spatial correlation intensity across the country. (2) Urbanization spatial correlation network structure characteristics are analyzed from national, regional and provincial scales. The structure of the spatial correlation network of urbanization is becoming more and more complicated, and the correlation paths have shifted from centralized to scattered. The differences in the correlation density between regional subgroups with different attributes have begun to shrink, and the high-level nodes have spread from the eastern to the central and western regions. (3) Further, the panel-vector auto-regression and panel quantile regression are used to test the interaction mechanism between urbanization spatial correlation intensity and correlation network centrality, which explains the effect of residents' income level and regional industrial structure on urbanization spatial correlation characteristics. The specialization of urbanization spatial correlation not only deepens the research on urbanization theory and methodology, but also provides a theoretical basis for the development of population urbanization and the adjustment of industrial space in China.

Clarifying the spatial pattern of population distribution, its influencing factors and regional differences at the township level is of great guiding significance for formulating sustainable development policies in ecologically fragile areas. Based on the population census data of Tibet at the township level in 2010, the population density and spatial factors were extracted. The density and clustering characteristics of the population distribution were analyzed by spatial statistical method. The multiple linear regression method and the random forest regression method were used to explore the population influencing factors and their regional differences of population distribution. The results showed that: (1) The population density of Tibet at the township level showed a strong spatial non-equilibrium. The general trend was high in the southeast and low in the northwest, and there was a strong spatial coupling between the main rivers and the main traffic trunks in high density area. (2) The "core-edge" characteristic of population clustering was obvious, and roughly to the wave of Borong (Nyalam County)-Gangni (Anduo County) as the demarcation line. (3) In the multiple linear regression method, the artificial surface index had the greatest influence on the population distribution, followed by the nighttime light index and road network density. (4) Random forest method was more accurate than multiple linear regression method to predict the population density, which can be used to sort the importance of the influencing factors. The influencing factors of the first six factors were the night light index, artificial surface index, road network density, industrial output value, GDP and multi-year average temperature, and these factors were positively correlated with population density. Among topographic factors, the contribution rate of elevation and slope was the largest, which was negatively correlated with population density. (5) The influencing factors and their interactions of population distribution in Tibet showed obvious regional differences. The valley was a gathering area for population in the study region, mainly in Lhasa River Valley, Nianchu River Valley and Sanjiang River Valley. (6) Through the analysis of random forest regression, the conceptual model can be used to express the influencing factors of population distribution, and the dominant factors were summarized as land use structure, road accessibility and urbanization level.

At present, there is a consistency that the focus of urban system research has shifted from the hierarchical to network paradigm. Based on an extensive review of existing studies, this paper investigates the shift of paradigm of China's urban system research since the 1980s, and discusses the development situation, main problems, and key topics of related research on urban network. The results show that: (1) After 2010, the amount of literature about urban network has increased dramatically and become the mainstream of urban system research, while the number of studies on the hierarchy system decreased. And the existing studies mainly focus on the urban system at national level and in the Yangtze River Delta. (2) The attribute data to a certain extent compensate for the lack of data in the early urban network research. Meanwhile, although the gravity model was widely used in these studies, its suitability is gradually decreasing. (3) In contrast, the relationship data have attracted scholars' attention, which is mainly applied to the urban system research from three perspectives: enterprise organization, traffic flow and information flow. However, due to the limitations of different perspectives, a comprehensive research on multiple perspectives has gradually become imperative. (4) The identification analysis has been the dominant theme of urban network research. Visualization analysis and design for urban system is mainly supported by directed unprivileged networks and undirected weighted networks. (5) Five important aspects of urban network research in future include adjusting the research framework of national urban network, examining the physical connections between cities directly without traffic data, measuring the horizontal linkages between the outside enterprises, analyzing and visualizing the directed weighted network research, and intensifying the geospatial characteristics of urban network research.

Based on the data of Chinese enterprises that entered the Fortune 500 list in 2015, this paper uses the eclectic model to construct the inter-city association network. Using the network analysis method, the spatial connection characteristics of 311 inter-city networks at prefecture level and above and 20 urban agglomerations networks in China are examined respectively. The research found that: (1) The overall connectivity of urban network is poor, the centripetal concentration is strong, and the network is not complete. The urban network connection shows a strong tendency of political center cities directivity, coastal cities directivity as well as resource-based cities directivity. The external economic dependence of each node city in the urban network is high, and the urban network structure has obvious flattening characteristics. The network of urban agglomerations is characterized by decentralization of power, differentiation of status and dependence on external connections. (2) The boundary effect of provinces, urban agglomerations and urban agglomerations clubs in the urban network is significant. The network evolution process is influenced by the provincial administrative district economy, the urban agglomerations economy and the urban agglomerations club economy. The size and number of central cities in the region and its surrounding areas have an impact on the provincial administrative district economy, the city agglomerations economy and the urban agglomerations club economy. (3) The function of cities is obviously divided in a multi-scale network. The large cities and regional central cities have a complete and more balanced function system than the small and medium-sized cities do. The radiation effect of three major urban agglomerations in coastal China is significant, while the dominant function of other urban agglomerations needs to be strengthened. (4) The cross-scale regional functional interaction effect of cities (clusters) is significant. The radiation-driven function of cities (clusters) is positively related to their self-agglomeration capabilities. This study provides support for the understanding of urban network model expansion and the spatial relation of urban network in China.