With its extremely strong transportation capability and tremendous cost of construction, high-speed railway not only brings rapid and significant effects on geo-economics and geopolitics, but also extends its trade pattern into the domains of international politics and diplomacy. China, Japan, Germany, and France are the major exporters of high-speed railway and all get involved in a keen competition in the international high-speed railway market. From the power and space perspectives of geopolitics and based on the national interests of security, development, and international influence, this article adopts an overlay analysis of the construction conditions, spatial interest pattern of exporting competitors, and China's competitive advantage, to demonstrate the geopolitical space and cooperation methods of China's high-speed railway diplomacy. The conclusions are as follows. First, the priority space of China's high-speed railway diplomacy includes Russia, Kazakhstan, India, Thailand, Vietnam, Malaysia, Indonesia, Australia, South Korea, the United States, and Brazil; Second, China can develop a multi-level cooperation with the United States, South Korea, Russia, Kazakhstan, and Australia. We also suggest that cooperation with other candidate countries should start with pre-engineering projects such as power generation and transmission. It is possible to cooperate with Brazil and Indonesia by pre-project engineering cooperation based on market demand. Third, in addition to cooperate with countries in the priority space, China can provide financial aid to Kyrgyzstan, Tajikistan, Pakistan, Bangladesh, Myanmar, Laos, Cambodia and other countries with careful consideration of the high-speed railway market demand and risk. Finally, considering only the economic interest, other countries with existing railway project cooperation may be the potential high-speed railway cooperators, such as Romania, Belarus, Estonia, Poland, Hungary, and Serbia.

Comparative studies on development tracks of Chinese and international geopolitical studies are seldom found in contemporary academia. This article reviews the development of Chinese and international geopolitical studies and compares their differences, and examines the prospect of Chinese geopolitical studies. This research found that there are significant differences between Chinese and international geopolitical studies on their essence, goals, contents, and basic understanding. With regard to their ideology and study area, mainstream contemporary international geopolitical studies are critical geopolitical research, and the diversification and generalization of its research subjects are increasingly obvious. Chinese geopolitical studies are practice-focused and mainly serve the national strategies. With regard to research method, international studies emphasize qualitative analysis and field research, and have deep understanding on specific areas. Chinese scholars focus on spatial and quantitative analyses, and pay special attention to macro-level spatial configuration and differentiation. This article concludes that Chinese scholars should investigate the essential relationship between geographic elements and geopolitics, strengthen cross-field research and make the results more reliable and practical, build a global worldview, widen the research fields, and ultimately found geopolitical thoughts with Chinese characteristics to assist the rejuvenation of China.