Abstract:    In the new era, "Internet+" has gradually become a powerful engine for China′s economic transformation, and it is having an increasingly far-reaching impact on various fields of economic and social development. Guiding Opinions on Actively Promoting the "Internet+" Action issued by the State Council clearly states that the goal of China′s "Internet+" is by 2025, "Internet+" has become an important driving force for social and economic innovation and development. The report of the 19th National Congress of the Communist Party of China also clearly stated that it is necessary to promote the deep integration of the Internet, big data, artificial intelligence and the real economy. This all marks that "Internet+" has risen to the national strategic height.
   In fact, under the guidance of relevant national policies in recent years, "Internet+" has become an irresistible trend, and China′s "Internet+" strategy has achieved remarkable results. According to statistics, as of December 2017, the number of Internet users in China reached 772 million, the Internet penetration rate exceeded the global average by 4.1%, and the number of basic resources such as the number of Internet IP addresses and international export bandwidth were among the highest in the world. However, the rapid growth of the above individual indicators does not mean that the "Internet+" quality or comprehensive level has been improved simultaneously. With the continuous deepening and release of the effectiveness of "Internet+", how to scientifically and reasonably evaluate and analyze the comprehensive level of China′s "Internet+" has become a realistic problem that needs to be solved urgently, which undoubtedly has important practical significance in terms of in-depth implementation of the "Internet+" strategy and network power in China. 
    Literature analysis found that existing research still has certain defects: Firstly, the use of a single indicator can only reflect one aspect of "Internet+", not enough to objectively reflect the reality of "Internet+"; secondly, few documents have measured the comprehensive level of "Internet+" in China over a long period of time; thirdly, there is no literature to systematically discuss the temporal and spatial evolution, spatial differences, source decomposition and convergence of China′s "Internet+" comprehensive level. The main marginal contribution of this paper lies in the first, designing China′s "Internet+" comprehensive indicator measurement system, constructing the inter-provincial "Internet+" comprehensive level index, and deeply analyzing its temporal and spatial characteristics. Second, measuring the spatial differences in "Internet+" level and revealing the source of the gap. Third, testing whether the "Internet+" comprehensive level is converged.
    Based on the design of the "Internet+" comprehensive index measurement system, this paper constructs the inter-provincial "Internet+" comprehensive level index by using panel data and global principal component analysis techniques of 30 provinces in China during 2006~2017, and further uses the Dagum Gini coefficient. The method and convergence theory analyze the spatial and temporal differentiation of China′s "Internet+" comprehensive level and its convergence. The main findings are: First, the comprehensive level of China′s "Internet+" is not high, and it has a significant spatial non-equilibrium feature of high in east and low in west with polarization. There is a large space for improvement, and they all show a steady upward trend year by year; Second, the overall spatial difference of "Internet+" comprehensive level is more obvious, and it is fluctuating. The regional gap is the main source of the overall spatial difference. The effect of the regional gap comes as the second, and the overlap between different regions. At the very least, the national and the three major regions have not shown the absolute β convergence of the "Internet+" development, but there is a clear "Matthew effect". Fourth, "Internet+" comprehensive level evolves with the conditional β convergence, but this situation only occurs in the eastern region, but not in the central and western regions.
     The conclusions of this paper have the following policy implications: First, the government must continue to increase the investment intensity of the "Internet+" related fields, and actively guide and amplify the effectiveness of social capital, such as through the construction of "Internet+" development funds, "Internet+" venture capital funds, "Internet+" technology incubator base and other means, continue to stimulate the regional "Internet+" vitality and improve the effectiveness of "Internet+", and then continue to enhance the "Internet+" comprehensive level; Second, we must pay full attention to the spatial non-equilibrium characteristics of the comprehensive development of "Internet+". Governments at all levels should change their respective concepts of politics. They should actively strengthen their own "Internet+" construction, and actively seek interaction and cooperation from among regions and regions, actively strengthen bench-marking, continue to make up for shortcomings. Regional policy of comprehensive level of coordinated development, actively breaking the spatial non-equilibrium constraint of "Internet+"; Third, narrowing the development gap between regions is a top priority for the implementation of "Internet+". On the one hand, the government must increase the inclination of the "Internet+" policy in the central and western regions, and fully guide its cooperation with the eastern region to promote the rapid development of the "Internet+" development elements to the central and western regions. On the other hand, the government should carry out overall planning and coordination of "Internet+", and form a new structure of inter-regional and urban-rural "Internet+" development interaction between regions, breaking time and space restrictions of "Internet+" and promoting regional "Internet+" integration process; Fourth, it is difficult for the central and western regions to rely solely on the market′s self-regulation mechanism to narrow the gap in the "Internet+" comprehensive level. The central government should strengthen and play the role of macroeconomic regulation and control. It is necessary to coordinate the development of different regions under the overall framework and promote regional development. 

Key words: "Internet+", overall level, Dagum Gini coefficient, spatial differentiation, convergence