Abstract: Current international society has entered an era of large-scale power transfer, and power tends to become more flexible and intangible. The proposed concept of geopolitical influence (geo-influence) conforms to this trend of power structure change in international relations, providing a new perspective for analyzing national comprehensive strength. Geo-influence includes hard power, soft power and interdependent power, which is an overall reflection of state external communication and coordination capacity. It can be an important index to measure national strength. This paper attempts to develop a method for measuring countries' national geo-influence. It defines the concept of geo-influence based on power theory, hard power and soft power theory and interdependence theory. Highlighting the dominant factors and the operational principles, the paper constructs an evaluation system and mathematical model of national geo-influence, estimates the comparative strength of China and South Asian countries in 2012, and calculates China's geo-influence values in different South Asian countries and the overall South Asian region over the past decade. The results show that: (1) The ranking of comprehensive strength ratio of China and South Asian countries in 2012 is India, Pakistan, Bangladesh, Sri Lanka, Nepal, Bhutan and Maldives in ascending order. In South Asian countries, the gap in comprehensive strength between China and India is the smallest, while the gap between China and Maldives are the largest. It indicates that geopolitical significance of a state, especially hard power is still an important support of comprehensive strength. (2) China's geo-influence in South Asia has shown an increasing trend, indicating that China's overall influence has been rising gradually in this region over the past decade. Among these countries, China's geo-influence value is high in Bhutan, Bangladesh and Nepal, but relatively low in Sri Lanka and Maldives. This demonstrates that geoinfluence is restricted by location and distance, with a spatially attenuating tendency. (3) Comprehensive strength is not proportional or positively correlated to a country's geo-influence. The gap in comprehensive strength between China and India is the smallest, but China's geo-influence in India lies in the middle range. On the other hand, the gap of comprehensive strength between China and Maldives is the greatest, but China's geoinfluence in Maldives is the lowest. (4) The gap in soft power between China and South Asian countries is small in terms of policy and institutional arrangements, national image and cultural exchanges. On the whole, the China's cultural influence in South Asia is weak, but it has been increasing slowly over the past decade.

Key words: China, geopolitical influence, modeling, South Asia