Abstract The goal of this study is to analyze China’s geo-economic strategy and contemporary relations with the two Koreas, and to probe China’s influence over the Korean peninsula. China is the only country with friendly and cooperative relations with the two Koreas among thepowerful states in Northeast Asia. Nevertheless,China’s influence over the Korean peninsula was still limited because of dynamic composition of international politicsin Northeast Asia. However, economic factor has recently become the focal point of international politics as each country’s foreign strategy is drafted by the pursuit ofits own economic interest. According to foreign economic situation of the two Koreas, China has become one of the two Koreas’ biggest cooperative partnerof foreign economic exchange. Moreover, on economic areas, China’s influence over the two Koreas has been expending as the two Koreas’ increasingly rely on China’s growing economy. Since the start of the 21st century, China’s economy had been leading the two Koreas’ economic development. However, new competition and friction on national interest and foreign economic strategy emerged, as the two Koreas start to exploit the geo-economic structure in Northeast Asia inpursuit of their economic development. These competition and frictionare difficult to solve since economic interest and national sovereignty are involved.They are still lurking threatswithin China’s cooperative relationships with the two Koreas.